AND THUS our conception of free will and necessity is gradually diminished or increased according to the degree of connection with the external world, the degree of remoteness in time, and the degree of dependence on causes which we see in the phenomenon of man's life that we examine. So that if we examine the case of a man in which the connection with the external world is better known, the interval of time between the examination and the act greater, and the causes of the action easier to comprehend, we form a conception of a greater element of necessity and less free will. If we examine a man in a less close dependence on external conditions, if his action is committed at a moment nearer the present, and the causes leading him to it are beyond our ken, we form a conception of a less element of necessity and a greater element of free will in his action.
But in neither case, however we shift our point of view, however clear we make to ourselves the connection in which the man is placed with the external world, or however fully comprehensible it may appear to us, however long or short a period of time we select, however explicable or unfathomable the causes of the act may be to us, we can never conceive of complete free will, nor of complete necessity in any action.
1. However carefully we imagine a man excluded from the influence of the external world, we can never form a conception of freedom in space. Every act of man's is inevitably limited by what surrounds him and by his own body. I raise my arm and let it fall. My action seems to me free; but asking myself could I raise my arm in any direction, I see that I moved it in the direction in which there was least hindrance to the action arising from bodies around me or from the construction of my own body. I chose one out of all the possible directions, because in that direction I met with least hindrance. For my action to be entirely free, it would have to meet with no hindrance in any direction. To conceive a man quite free, we have to conceive him outside of space, which is obviously impossible.
2. However near we bring the time of criticism to the time of action, we can never form a conception of freedom in time. For if I examine an act committed a second ago, I must still recognise that it is not free, since the act is irrevocably linked to the moment at which it was committed. Can I lift my arm? I lift it; but I ask myself: Could I not have lifted my arm in that moment of time that has just passed? To convince myself of that, I do not lift my arm the next moment. But I am not abstaining from lifting it that first moment of which I asked myself the question. The time has gone by and to detain it was not in my power, and the hand which I then raised and the air in which I raised it are not the same as the hand I do not raise now or the air in which I do not now raise it. The moment in which the first movement took place is irrevocable, and in that moment I could only perform one action, and whatever movement I had made, that movement could have been the only one. The fact that the following moment I abstained from lifting my arm did not prove that I could have abstained from lifting it. And since my movement could only be one in one moment of time, it could have been no other. To conceive it to oneself as free, one must conceive it in the present on the boundary between the past and the future, that is, outside time, which is impossible.
3. However we increase the degree of difficulty of comprehending the causes of the act, we never reach a conception of complete free will, that is, absolute absence of cause. Though the cause of the expression of will in any act of our own or another's may be beyond our ken, it is the first impulse of the intellect to presuppose and seek a cause, without which no phenomenon is conceivable. I raise my arm in order to perform an act independent of any cause, but the fact that I want to perform an act independent of any cause is the cause of my action.
But even if by conceiving a man entirely excluded from external influence, and exercising only a momentary act in the present, not called forth by any cause, we were to reduce the element of necessity to an infinitesimal minimum equivalent to nil, we should even then not have reached a conception of complete free will in a man; for a creature, uninfluenced by the external world, outside of time, and independent of cause, is no longer a man.
In the same way we can never conceive a human action subject only to necessity without any element of free will.
1. However we increase our knowledge of the conditions of space in which a man is placed, that knowledge can never be complete since the number of these conditions is infinitely great, seeing that space is in finite. And so long as not all the conditions that may influence a man are defined, the circle of necessity is not complete, and there is still a loophole for free will.
2. Though we may make the period of time intervening between an act and our criticism of it as long as we choose, that period will be finite, and time is infinite, and so in this respect too the circle of necessity is not complete.
3. However easy the chain of causation of any act may be to grasp, we shall never know the whole chain, since it is endless, and so again we cannot attain absolute necessity.
But apart from that, even if, reducing the minimum of free will till it is equivalent to nil, we were to admit in some case—as, for instance, that of a dying man, an unborn babe, an idiot—a complete absence of free will, we should in so doing have destroyed the very conception of man, in the case we are examining; since as soon as there is no free will, there is no man. And therefore the conception of the action of a man subject only to the law of necessity, without the smallest element of free will, is as impossible as the conception of a completely free human action.
Thus to conceive a human action subject only to the law of necessity without free will, we must assume a knowledge of an infinite number of conditions in space, an infinitely long period of time, and an infinite chain of causation.
To conceive a man perfectly free, not subject to the law of necessity, we must conceive a man outside of space, outside of time, and free from all dependence on cause.
In the first case, if necessity were possible without free will, we should be brought to a definition of the laws of necessity in the terms of the same necessity, that is, to mere form without content.
In the second case, if free will were possible without necessity, we should come to unconditioned free will outside of space, and time and cause, which by the fact of its being unconditioned and unlimited would be nothing else than content without form.
We should be brought in fact to these two fundamental elements, of which man's whole cosmic conception is made up—the incomprehensible essence of life and the laws that give form to that essence.
Reason says: 1. space with all the forms given it by its visibility—matter—is infinite, and is not thinkable otherwise.
2. Time is infinite movement without one moment of rest, and it is not otherwise thinkable.
3. The connection of cause and effect has no beginning, and can have no end.
Consciousness says: 1. I alone am, and all that exists is only I; consequently I include space.
2. I measure moving time by the unchanging moment of the present, in which alone I am conscious of myself living; consequently I am outside of time, and
3. I am outside of cause, since I feel myself the cause of every phenomenon of my life.
Reason gives expression to the laws of necessity. Consciousness gives expression to the reality of free will.
Freedom unlimited by anything is the essence of life in man's consciousness. Necessity without content is man's reason with its three forms of thought.
Free will is what is examined: Necessity is what examines. Free will is content: Necessity is form.
It is only by the analysis of the two sources of knowledge, standing to one another in the relation of form and content, that the mutually exclusive, and separately inconceivable ideas of free will and necessity are formed.
Only by their synthesis is a clear conception of the life of man gained.
Outside these two ideas—in their synthesis mutually definitive as form and content—no conception of life is possible.
All that we know of men's life is only a certain relation of free will to necessity, that is, of consciousness to the laws of reason.
All that we know of the external world of nature is only a certain relation of the forces of nature to necessity, or of the essence of life to the laws of reason.
The forces of the life of nature lie outside us, and not subject to our consciousness; and we call these forces gravity, inertia, electricity, vital force, and so on. But the force of the life of man is the subject of our consciousness, and we call it free will.
But just as the force of gravitation—in itself incomprehensible, though felt by every man—is only so far understood by us as we know the laws of necessity to which it is subject (from the first knowledge that all bodies are heavy down to Newton's law), so too the force of free will, unthinkable in itself, but recognised by the consciousness of every man, is only so far understood as we know the laws of necessity to which it is subject (from the fact that every man dies up to the knowledge of the most complex economic or historic laws).
All knowledge is simply bringing the essence of life under the laws of reason.
Man's free will is distinguished from every other force by the fact that it is the subject of man's consciousness. But in the eyes of reason it is not distinguished from any other force.
The forces of gravitation, of electricity, or of chemical affinity, are only distinguished from one another by being differently defined by reason. In the same way the force of man's free will is only distinguished by reason from the other forces of nature by the definition given it by reason. Free will apart from necessity, that is, apart from the laws of reason defining it, is in no way different from gravitation, or heat, or the force of vegetation; for reason, it is only a momentary, indefinite sensation of life.
And as the undefined essence of the force moving the heavenly bodies, the undefined essence of the force of heat, of electricity, or of chemical affinity, or of vital force, forms the subject of astronomy, physics, chemistry, botany, zoology, and so on, so the essence of the force of free will forms the subject matter of history. But even as the subject of every science is the manifestation of that unknown essence of life, yet that essence itself can only be the subject of metaphysics, so too the manifestation of the force of free will in space, and time, and dependence on cause, forms the subject of history, but free will itself is the subject of metaphysics.
In the experimental sciences, what is known to us we call the laws of necessity; what is unknown to us we call vital force. Vital force is simply an expression for what remains unexplained by what we know of the essence of life. So in history what is known to us we call the laws of necessity; what is unknown, we call free will. Free will is for history simply an expression for what remains unexplained by the laws of men's life that we know.
因此，如果我们考察一个人处于这样一种情况：他与外部世界的联系是最为人所共知的，他完成行为与判断这一行为的时间距离是极长的，行为发生的原因是最容易理解的，那么，我们就得到最大的必然性和最小的自由意志的观念。如果我们考察一个与外部条件的关系最少的人，他完成行为的时间离现在非常近，他的行为发生的原因是我们难以理解的，那么，我们就能得到最小的必然性和最大的自由意志的观念。
但是，不论在前一种情形或者在后一种情形，不论我们怎样改变我们的看法，不论我们怎样弄清楚人与外部世界之间的关系，或者不论我们怎样觉得那种关系无法弄清楚，不论把时期怎样延长或缩短，不论我们觉得原因是可知或不可知，我们都不能想象出完全的自由或完全的必然性。
一、不论我们怎样想象一个人如何不受外部世界的影响，我们永远得不到在空间上自由的观念。人的任何一次行动都不可避免地受他自己的身体和他周围事物的制约。我举起胳膊，然后把它放下来。我觉得我的行动是自由的；但是我问问自己：我能不能朝各个方向举起胳膊呢？于是我看出，我是朝着行动最不受周围的事物和我自己的身体构造的妨碍的方向举起胳膊的。我从各个可能的方向中选出一个，因为在这个方向上障碍最少。如若要我的行动自由，就必须使我的行动不致于碰上任何障碍。如若要想象一个人自由，我们就得想象他超出空间以外，那显然是不可能的事。
二、不论我们怎样使判断的时间接近于行动的时间，我们总是得不到时间上自由的观念。因为，假如我考察一秒钟以前完成的一种行为，我们仍然认为那种行为是不自由的，因为它是与完成它的那一时刻分不开的。我能举起胳膊吗？我能把它举起来；但是我问问自己：我能在已经过的那个时刻不举起胳膊吗？要使我自己相信这一点，我在下一个时刻就不举起胳膊。但是，我并非在向我自己提出关于自由的问题的那第一个时刻不举起它的。时间已经过去了，留住它并非取决于我，我在那时举起的胳膊已经不是我在这时不举的胳膊了，我在举起胳膊时的空气也已经不是现在围绕着我的空气了。完成第一次活动的那个时刻是一去不复返的，在那个时刻我也只能完成一种活动，不论我完成哪种活动，那种活动只能是唯一的一种。在那个时刻之后，我不再举起胳膊，并不是证明我能不举它。因为在那一个时刻我只能做一个动作，它不可能又是别的任何动作。要把我的动作想象作自由的，就必须想象现在的它，又是过去和将来之间的它，就是说，超出时间以外的它，这是不可能的。
三、不论对原因的理解有多么大的困难，我们永远得不出一种完全自由的观念（就是说，完全没有原因）。不论我们对我们自己或别人的任何行动中的意志表现的原因是多么难以理解，智能的第一个要求就是假设和探求一种原因，因为没有原因的任何现象都是不堪想象的。我举起胳膊进行活动，与任何原因无关，但是我要做一个没有原因的动作，这就是我的行动的原因。
但是，即使想象一个完全不受一切影响的人，只考虑他现在这一瞬间的行动，假定他这种行动不是由任何原因引起的，认为必然性的残余小得等于零，我们也得不出人有完全自由的观念，因为不受外部世界的影响，超出于时间以外，与原因毫无关联的生物，已经不是人了。
同样，我们也绝不能设想一个人的行为完全没有自由，只受必然性法则的支配。
一、不论我们怎样增长我们对人所处的空间的条件的知识，这种知识永远是无穷无尽的，因为这些条件的数目是无限的，正如空间是无限的一样。因此，既然不能确定所有的条件，不能确定人所受到的一切影响，那就不会有完全的必然性，也就是存在着一定成分的自由。
二、不论我们怎样延长我们考察现象和判断那种现象之间的一段时间，而这段时间是有限的，时间是无限的，因此，在这方面也不可能有完全的必然性。
三、不论行为发生的原因这条锁链怎样容易了解，我们也永远不会了解这全部锁链，因为它是无穷无尽的，因此我们还是永远得不出完全的必然性。
但是，除此而外，即使假定残余的意志自由小得等于零，我们仍认为，在某种情形下，例如在一个行将死去的人、一个未生的胎儿，或者一个白痴的处境中，根本没有意志自由，这样我们就连我们所考察的那个人的概念也毁灭了；因为一旦没有意志自由，也就没有人了。因此，一个人的行动受必然性法则的支配，没有任何的意志自由，这种观念正如一个人完全自由行动的观念一样，是不可能存在的。
因此，要设想一个人的行为受必然性法则的支配，没有丝毫的意志自由，我们就得假定，我们知道已有无限数量的空间条件，·无·限长的时限和·无·限多的原因存在。
要设想一个人完全自由，不受必然性法则的支配，我们就得把他想象成一个超空间，超时间，与任何原因无关的人。
在第一种情形下，假如没有自由的必然性是可能存在的，我们就由那个必然性自身得出必然性法则的定义，也就是得出一种没有内容的单纯的形式。
在第二种情形下，假如没有必然性的自由是可能存在的，我们就得到一种超空间、超时间和无原因的无条件的自由，这种自由本身是无条件的、无限制的，那就是什么也没有或是没有形式的单纯的内容。
一般地说，我们得到那形成人类全部宇宙观的两个根据——不可知的人生实质和确定这种实质的法则。
理性表明：一、空间以及赋予它本身可见性的各种形式——物质，是无限的，不然就是不堪想象的。二、时间是没有瞬间停顿的无限的运动，不然就是不堪想象的。三、原因和结果的联系没有起点，也不可能有终点。
意识表明：一、只有我一人，一切存在都不外乎是我；因此，我包括空间。二、我用现在静止的一瞬间来测量流逝的时间，只有现在这一瞬间我才意识到我还活着；因此，我是超出时间之外的。三、我是超出原因之外的，因为我觉得我生活中的每一现象产生的根源就是我自己。
理性表达出必然性的法则，意识表达出意志自由的实质。
不受任何限制的自由是人的意识中的生活实质。没有内容的必然性是有三种形式的人的理性。
自由是受考察的对象。必然是考察的对象。自由是内容。
必然是形式。
只有把两种认识的源泉分开时——这两种认识的关系才算是形式和内容的关系，这就得出单独的、互相排斥的和无法理解的自由和必然性的概念。
只有把它们互相结合时，才能得出关于人类生活的明确概念。
在这互相规定为形式和内容结合的两个概念之外，任何生活都是不堪想象的。
我们对人类生活所知道的一切，只不过是自由和必然的一定关系，这也就是意识和理性法则的关系。
我们对外部自然界所知道的一切，只不过是自然力和必然性的一定关系，或生活的实质和理性法则的一定关系。
大自然的生命力存在于我们之外，不为我们所认识，我们就把这些力叫作引力、惰力、电力、离力、等等；但是人的生命力是为我们所认识的，我们就把它叫做自由。
但是，正如人人所感觉到的，而其本身则无法理解的万有引力一样，我们对那支配它的必然性法则知道多少（从一切物体都有重量这个起码知识，到牛顿定律），我们就能对他了解多少，同样，人人意识到，而其本身则无法理解的自由意志力，我们每个人对那支配它的必然性法则能认识多少（从每个人都会死亡这一事实，到最复杂的经济规律或者历史规律的知识），我们就能对它了解多少。
一切知识只不过是把生活的实质归纳为理性的法则罢了。
人的自由意志与其他任何力量不同就在于，人能认识到自由意志的力量；但是对理性来说，自由意志力与别的任何力量并无不同。万有引力、电力或化学亲合力，彼此之间的区别，只在于理性给它们下了不同的定义。同样对理性来说，人的自由意志力与别种自然力的区别，也只是在于理性给它下的定义。自由如脱离必然性，就是说，脱离规定它的理性法则，就与万有引力、或热力、或植物生长力并无任何区别，对理性来说，自由只不过是瞬息间的、无法确定的生命的感觉。
正如无法确定的推动天体的力的实质、无法确定的热力、电力或化学亲合力，或生命力的实质，构成了天文学、物理学、化学、植物学、动物学，等等的内容一样，自由意志力的实质构成了历史的内容。但是，正如每种科学研究的对象是未知的生活实质的表现，而这实质的本身只能是形而上学的研究对象一样，人的自由意志在空间、时间和因果关系中的表现，构成历史的研究对象；而自由意志本身是形而上学研究的对象。
在有关生物体的科学中，我们把已知的东西叫作必然性的法则；把未知的东西叫做生命力。生命力不过是对我们所知道的生命实质以外的未知的剩余部分的一种说法。
历史中也是如此：我们把已知的东西叫作必然性的法则；把未知的东西叫作自由意志。就历史来说，自由意志不过是对我们已知的人类生活法则中未知的剩余部分的一种说法。