The Remaining Works of Benedictus de Spinoza

And indeed, there is reason why such a reduction of all finite things to an infinite unity should be most appealing to the intellect or logical faculty. The act of thinking consists solely in the thinker perceiving the unity of those things which, in another respect, are diverse, or even could be most diverse. a is predicated of b insofar as a is understood to be inherent in b in the sense currently under discussion. Whence it is clear, and has long since been shown, that the formal or logical investigation of truth is to be compared to arithmetical permutation, whereby two numbers appearing under different guises remain and stay the same, just as 2 x 3 = 6. It follows spontaneously that in that very formal investigation of truth, there can be no higher canon than this: that multiple things must always be reduced to one. From this, thinkers neither cease nor can they cease to elevate not only individuals to species and species to general classes, but also to refer all derived principles or applied laws to one principle in thought and to deduce them from there. Nor is it difficult to understand that everything with 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), and indeed, is now an ingrained part of the mind. Hence, if the thinker is called the subject, it is evident that while he thinks, he must be called the subject-object, or that one common source of the subjective and objective.