I. "We have been told that the searcher for truth should proceed on lines precisely similar to those followed by the scientist. But how can the metaphysician do this, having no such means of demonstrating the validity of his conclusions, as are furnished by science?" Reply. -- This objection proceeds upon the common rationalistic assumption that truth (other than mathematical) can be known with certitude only through our senses, by observation and experiment. That this principle is radically false science is herself our witness, for the discoveries of which she is rightly proud are the result, not directly of sensible observation, but of inferences from observed phenomena. The soundness of such inferences depends upon first principles recognised by reason as self-evident, and these are exactly similar to those upon which philosophers rely. The laws, for instance, of motion, gravitation, conservation of energy, chemical reaction, light, sound, heat, electricity, nagnetism, -- are not and can never be the objects of direct observation. All that such observation can possibly disclose are certain concrete individual facts which of themselves would be devoid of interest or importance, as, for instance, that unsupported stones fall to earth; that friction produces heat; that an oar in the water seems to be bent; that we see the lightning flash before we hear the peal of thunder. It is the mind that from a few such instances deduces laws of universal application, which it extends with confidence to the whole universe, and it is able to do so only because of its reliance upon the first principles above mentioned. And although these are incapable of proof -- as first principles necessarily must be -- they are more certain to us than anything else. Such principles are, that all phenomena must have a cause, and one capable of producing them; that the same thing cannot be, and not be, at the same time; that our reason and the evidence of our senses are trustworthy guides. To these, scientists commonly add what is not really a first principle but an inference from their observation of Nature -- namely, that she is always and invariably uniform in her operation, and in like circumstances produces ever identically the same results. It is the assurance of this truth that alone makes science possible.
Still more obvious is it that the doctrines which rationalists most earnestly maintain are not the direct result of observation and experiment, as, for example, the Evolution theory in general, or Darwinism in particular, or the spontaneous origin of life. It is not because one species has ever actually been found to produce another, or because life has been proved to originate from lifeless matter, that men believe such things to have occurred, but because no other explanation of existing phenomena can be discovered which is in accordance with certain principles assumed by those who adopt these conclusions.
It is here that the orthodox philosopher -- the "metal physician" -- parts company with the freethinker. Starting with the same fundamental first principles which must underlie all sound reasoning, he insists on following them to their legitimate conclusions, and refuses to be restricted from doing so in deference to assumptions for which he can find no rational warrant. It is not against science that he sets his face, but against the unscientific employment of scientific data to reach conclusions which reason does not sanction.
II. "You stated at the outset of your lecture that when science has spoken on any point there is an end of mental freedom, as no one can think otherwise than she bids him. Is it not true, however, that science never dogmatizes, but always leaves scope for further knowledge, and does not bind us to accept anything as being absolute truth?"
Reply. -- There is a certain ambiguity about the word "dogmatize." Properly, it should signify to enunciate "dogmas," or definite articles of belief as absolutely true. In practice, however, it is limited to the enunciation of dogmas which are devoid of reasonable grounds, and the imposition of beliefs which have to be accepted blindly on the word of pretended authority. It seems to be commonly assumed that these two meanings are identical, and that whosoever professes to teach doctrines which are absolutely and everlastingly true must be an impostor, and may be at once set down as dogmatizing in the worst sense of the word. It is simply upon this ground that the charge is so freely brought against the Church -- but obviously this is to beg the question, and take for granted that she has no solid ground for what she teaches. It is manifest, however, that if there were upon earth a teacher having, as the Church claims to have, the assistance of a higher Wisdom revealing truth beyond the possibility of error, he could do no otherwise than the Church actually does, and would stultify himself were he to act otherwise. And unless it can be shown that the Church has no such supernatural assistance, or that such assistance is impossible, it is unreasonable to assume that because she teaches as she does she must be wrong.
On the other hand -- to say nothing of those who in the name of science dogmatize on matters whereof science knows nothing, of whom there are too many -- it is clear that in proportion as science attains real knowledge, she necessarily becomes dogmatic, and peremptorily demands acceptance for her conclusions. And if she must always leave scope for further knowledge, it is because she has no means of attaining to the fulness of truth, and even within the limits of her own proper domain finds herself ever confronted by unsolved mysteries. So far as her knowledge goes she lays down the law unhesitatingly, but cannot be said to dogmatize, because she knows her teaching to be true. And if the Church speaks with equal confidence of matters whereof science knows nothing, it is because she claims a source of knowledge altogether transcending what our natural power affords.
III. "If we are to say that intelligence must have existed eternally in the First Cause, because it exists now, why not say that fingers and toes and digestive organs must have similarly existed from the beginning, because they exist in man?"
Reply. -- The Cause must include in itself all that is derived from it, but not necessarily in the same way. The man who makes a musical instrument -- a violin or organ -- must have music in him, or his creations would never produce it; but it does not follow that he must be composed, as they are, of catgut and pipes. As man possesses intelligence, his Creator must possess intelligence, including all the powers possessed by His creature but in a manner so immeasurably higher as to make comparison impossible.
IV. "How would the Church be affected were scientists to succeed in producing life from dead materials?"
Reply. -- Not at all. Neither should we be any nearer full knowledge as to vital origins. For, were matter proved to contain the potentiality of life, the question would still remain -- How did it come to be so?
V. "Is it not true that we cannot know anything regarding God except through the manifestations of Nature?"
Reply. -- It is true that all premises or data of inference come to us from external nature through our senses, but knowledge results only from the action upon these data of our own mind, with its intuitive recognition of first principles alike in the intellectual and the moral order. From examination of the outer world and of itself, the mind can form an idea of the Author of both, utterly inadequate, it is true, but right so far as it goes. It can be sure that He who made man must have all that man has, though He must also have immeasurably more.