The Collected Works of Benedict de Spinoza

He had perceived that the knowledge of the union which the mind has with the whole of nature was necessary for him to understand the true good. If only the philosopher had begun his science from the knowledge of this mind itself, by separating those things which he found to be subject to variations in his own mind from the necessary and universal ideas which shine like a beacon, unmoved, for a man investigating the true good—that is, for one who intends to follow the practical reason and its absolute dictates, and who is about to embrace most willingly not that prudence accommodated to vain and fleeting circumstances, but that holiness which, as the Apostle says (1 John 2:17), is eternal and not to be changed. But the method of that age was different. The inveterate custom, as if transfused into Spinoza from Descartes, was that the beginning must always be made from constructing metaphysics, and that the "being" τὸ ὂν of things must be explained before all else. The knowledge of our mind leads through necessary arguments to God. But those mortals who are able to ascend from the former to the latter do not descend with equal success from the infinite to the finite. They begin, namely, from that which, because it is more remote from our knowledge, human imagination seems to itself to grasp more easily than reason. Once this is done, if an error is admitted in the metaphysical treatment of the Infinite, it is both very difficult to detect and yet subtly insinuates itself into all the remaining articles of the system. Therefore, having become more cautious due to the dangers of the earlier philosophers, they have taught more correctly and successfully that all moral doctrine should be independent of metaphysical dogmas, derived from that which is absolute within the human mind.