The Works of Benedictus de Spinoza

...the concept of pure extension anywhere. Having forgotten the origin from which he drew it, he was persuaded that he intuited those two attributes through a clear idea in God, or the Infinite. Furthermore, if he had set before himself that same contemplation of the mind, or of himself, with deliberate study as that primary thing from which the work must proceed, he would undoubtedly have been compelled to discern to Velle the Will or the spontaneity of willing as a faculty that is entirely unique and, in a being that is something unto itself, just as primitive as to Cogitare Thinking. Had this been done, his entire Ethics—which now refers everything to thought and therefore necessarily excludes moral freedom—could not have failed to be formed in a far different manner in that which pertains to human beings. Indeed, in the theological principles he put forth, if he had felt compelled to consider to perfecte (h. e. sancte) velle perfect (i.e., holy) willing no less than to cogitare thinking or scire knowing as a primitive pneumatikēn spiritual faculty, and thus to number it among those attributes of God of which we can have a clear idea, he would not have thought that the notion of infinite spontaneity or pure volition was excluded from the clear idea of the Most Perfect.

Sed, another point also needs to be indicated, which seems to touch the head of the Spinozistic system. Namely, that doctrine recommends itself marvelously by its simplest unity, encompassing absolutely everything through its hen kai pan one and all. Everything seems to be reduced to its one source, from which they do not even emanate, but in which they truly remain, such that this Pantheism is a system...