must perfectly agree to it, To say the idea of extension agrees to any thing, is to say it is extended. The free-thinker may now triumph in his turn; and having found there are impressions and ideas really extended, may ask his antagonists, how they can incorporate a simple and indivisible subject with an extended perception? All the arguments of Theologians may here be retorted upon them. Is the indivisible subject, or immaterial substance, if you will, on the left or on the right hand of the perception? Is it in this particular part, or in that other? Is it in every part without being extended? Or is it entire in any one part without deserting the rest? 'Tis impossible to give any answer to these questions, but what will both be absurd in itself, and will account for the union of our indivisible perceptions with an extended substance.
This gives me an occasion to take a-new into consideration the question concerning the substance of the soul; and tho' I have condemn'd that question as utterly unintelligible, yet I cannot forbear proposing some farther reflections concerning it. I assert, that the doctrine of the immateriality, simplicity, and indivisibility of a thinking substance is a true atheism, and will serve to justify all those sentiments, for which Spinoza is so universally infamous. From this topic, I hope at least to reap one advantage, that my adversaries will not have any pretext to render the present doctrine odious by their declamations, when they see that they can be so easily retorted on them.
The fundamental principle of the atheism of Spinoza is the doctrine of the simplicity of the universe, and the unity of that substance, in which he supposes both thought and matter to inhere. There is only one substance, says he, in the world; and that substance is perfectly simple and indivisible, and exists every where, without any local presence. Whatever we discover externally by sensation; whatever we feel internally by reflection; all these are nothing but modifications
of that one, simple, and necessarily existent being,