Part Three

Origin of the First Principles of Reasoning

CHAPTER 2

The third and fourth principles: substance and cause

567. The principle of contradiction depends on the principle of knowledge (cf. 565), which is a necessary fact expressed as follows: 'The object of thought is being.' It is the principle of all principles, the law of intelligent nature, and the essence of intelligence.
The second principle is that of contradiction, derived directly from the first: 'Being and not-being cannot be thought at one and the same time.'
The third is the principle of substance: 'Accidents cannot be thought without substance.'
The fourth principle is cause: 'A new entity cannot be thought without a cause.'

568. Accidents are perceived through actions on us and can also be called by the general name, happenings, which is very appropriate because they are something that happens to substance without being necessary to it. There is no difference between accidents and effects except that accidents are considered as one thing with the substance and terms of it, while effects are considered separate from their cause, and proper to some other ens. With that understood, the way we deduce the principle of cause will serve as an example for deducing the principle of substance (cf. 52-54), which the reader can deduce for himself.

569. The principle of cause derives from the principle of knowledge, and hence from the principle of cognition, in the following way. The principle of cause can be stated as: 'Every happening (anything that begins) has a cause that produces it.' We found this expression elsewhere and analysed it; at this point we must recall the analysis.
'Every happening has a cause that produces it.' This proposition means exactly the same as the following: 'It is impossible for our intelligence to think a happening without thinking a cause that produced it.' To show that 'a happening without a cause cannot be thought', we must show that 'the concept of a happening without a cause involves contradiction.' Once this is demonstrated, we will have deduced the principle of cause from the principle of contradiction.

The demonstration is as follows: to say 'What does not exist, acts' is a contradiction. But a happening without a cause means 'What does not exist, acts.' Therefore a happening without a cause is a contradiction. The proofs follow.
As regards the major: to conceive mentally an action (a change) without an ens, is to conceive without conceiving, which is a contradiction. Indeed, the principle of knowledge states: 'The object of thought is ens'; therefore without an ens, we cannot mentally conceive. To conceive an action without conceiving an ens that performs the action, is to conceive without conceiving. Therefore to apply the action to something that does not exist is a contradiction in terms, which was to be proved.

As regards the minor: a happening is an action (a change). If this action has no cause, it is conceived by itself, without belonging to an ens; there is then an action without ens or, which is the same, what does not exist, acts. Thus the minor is proved (cf. 350-352).

The principle of cause therefore derives from the principle of contradiction, and both derive from the principle of knowledge, which is only the idea of being in its application. As such, this idea takes the form of a principle and is expressed in a proposition, when considered in relationship with human reasoning, of which it is the formal cause.