e only faculty whereby we can judge of things. But it gives no completed
system of knowledge and in matters of fact affords only probable
conclusions. In this emphatic declaration, that knowledge of the course of
nature is merely probable, Butler is at one with Hume, who was a most
diligent student of the bishop's works. What can come nearer Hume's
celebrated maxim--"Anything may be the cause of anything else," than
Butler's conclusion, "so that any one thing whatever may, for aught we know
to the contrary, be a necessary condition to any other"?

It is this strong grasp or the imperfect character of our knowledge of
nature and of the grounds for its limitation that makes Butler so
formidable an opponent to his deistical contemporaries. He will permit no
anticipations of nature, no _a priori_ construction of experience. "The
constitution of nature is as it is," and no system of abstract principles
can be allowed to take its place. He is willing with Hume to take the
course of experience as the basis of his reasoning, seeing that it is
common ground for himself and his antagonists. In one essential respect,
however, he goes beyond Hume. The course of nature is for him an unmeaning
expression unless it be referred to some author; and he therefore makes
extensive use of the teleological method. This position is assumed
throughout the treatise, and as against the deists with justice, for their
whole argument rested upon the presupposition of the existence of God, the
perfect Ruler of the world.

The premises, then, with which Butler starts are the existence of God, the
known course of nature, and the necessary limitation of our knowledge. What
does he wish to prove? It is not his intention _to prove God's perfect
moral government over the world or the truth of religion_. His work is in
no sense a philosophy of religion. His purpose is entirely defensive; he
wishes to answer objections that have been brought against religion, and to
examine certain difficulties that have been alleged as insuperable. And
this is to be effected in the first place by showing that from the
obscurities and inexplicabilities we meet with in nature we may reasonably
expect to find similar difficulties in the scheme of religion. If
difficulties be found in the course and constitution of nature, whose
author is admitted to be God, surely the existence of similar difficulties
in the plan of religion can be no valid objection against its truth and
divi