The Remaining Works of Benedict de Spinoza

And indeed, there is a reason why such a reduction of all finite things to an infinite unity should be most pleasing to the intellect or logical faculty. The act of thinking consists precisely in this: that the thinker perceives the unity of those things which, in another respect, are diverse, or indeed can be most diverse. a is predicated of b, insofar as it is understood that τῳ to b belongs τὸ the a in the very sense about which the question is posed. Hence it is clear, and has long since been shown, that the formal or logical investigation of truth is to be compared with arithmetical permutation, by which two numbers appearing under a different guise nevertheless are and remain the same, just as 2 x 3 = 6. It follows of its own accord that in that very formal investigation of truth there can be no higher canon than this: that more things are always to be reduced to one, from which thinkers not only do not cease—and cannot cease—to elevate individuals to species and species to general classes, but also to refer all grounded things or applied laws to one principle in thought, and from there to deduce them. Nor is it difficult to understand that everything about which thought is occupied, and which they call an object, can be reached and treated by thinking and willing, not insofar as it exists outside of thought, but insofar as it is present to the mind (whether as an existing thing or as something merely thinkable), or indeed is even an inherent part of the mind. Whence, if the thinker is called the subject, it becomes clear that he himself, while thinking, must be called and is completely a subject-object, or that one common source of the subjective and objective.