Spinoza formulated the profoundly important principle that *all determination is negation*. To determine a thing is to cut it off from some sphere of being and so to limit it. To define is to set boundaries. To say that a thing is green limits it by cutting it from the sphere of pink, blue, or other-coloured things. To say that it is good cuts it off from the sphere of evil. This limitation is the same as negation. To *affirm* that a thing is within certain limits is to *deny* that it is outside those limits. To say that it is green is to say that it is not pink. Affirmation involves negation. Whatever is said of a thing denies something else of it. All determination is negation.This principle is fundamental for Hegel also, but with him it takes rather the converse form that *all negation is determination*. Formal logicians will remind us that we cannot simply convert Spinoza’s proposition. But it is sufficient to point out in reply that not only does affirmation involve negation; negation likewise involves affirmation. To say that a thing belongs to one class is to affirm that it belongs to some other class,—though we may not know what that class is. Positive and negative are correlatives which mutually involve each other. To posit is to negate: this is Spinoza’s principle. To negate is to posit: this is Hegel’s.When, therefore, we meet Hegel talking about “the portentous power of the negative,” we have to consider that for him negation is the very process of creation. For the *positive* nature of an object consists in its determinations. The nature of a stone is to be white, heavy, hard, etc. And since all determinations are negations, it follows that the positive nature of a thing consists in its negations. Negation, therefore, is of the very essence of positive being. And for the world to come into being what is above all necessary is the force of negation, “the portentous power of the negative.” The genus only becomes the species by means of the differentia, and the differentia is precisely that which carves out a particular class from the general class by excluding, i.e., negating, the other species. And the species again only becomes the individual in the same way, by negating other individuals. These thoughts are no causal reflections of Hegel. They underlie his entire system. We must get to understand that these three ideas, determination, limitation, and negation, all involve each other.”—from_The Philosophy of Hegel_
W.T. Stace