intuitions of that faculty, and truths of sensation are intuitions of the senses. I shall therefore speak of self-evident truths of reason, and self-evident truths of sensation. I must assume that you possess some knowledge of psychology, and take it for granted that you understand the difference between the intuitions of reason, and the intuitions of sense.

By self-evident truths of reason, then, I mean that class of truths that are directly intuited and affirmed by that faculty, in the light of their own evidence, and by virtue of its own laws, whenever they are so stated that the terms of the proposition in which they are conveyed are understood. They are not arrived at by reasoning, or by evidence of any kind except what they have in themselves. As soon as the terms of the propositions in which they are stated, are understood, the reason instantly and positively affirms their truth. It is unnecessary and preposterous to attempt any other proof of this class of truths than to frame a perspicuous statement of them. Nay, it is positively injurious, because absurd, to attempt to prove-in the common acceptation of the term prove a self-evident truth of reason. All attempts to prove such truths by reasoning, involve an absurdity, and are as much a work of supererogation, as it would be to attempt to prove that you see an object with your eyes fully open and set upon it.

The mathematical axioms belong to this class.

The self-evident truths of reason are truths of certain knowledge. When once so stated, or in any way presented to the mind as to be understood, the mind does not merely believe them, it knows them to be absolutely true. That is, it perceives them to be absolute truths, and knows that it is impossible that they should not be true. Although this class of truths are never arrived at by reasoning, yet much use is made of them in reasoning, since the major premise of a syllogism is often a self-evident truth of reason.

This class of truths are affirmed by a faculty entirely distinct from the understanding, or that power that gains all its knowledges from sense. It takes cognizance of a class of truths that from their nature, forever lie concealed from the senses, and consequently from the understanding. Sensation can never give us the abstract truths of mathematics. It can never give us the absolute, or the infinite. It can not give moral law, or law at all. Sensation can give facts, but not laws and principles.

That God, and space, and duration, are infinite; that all God's attributes must be infinite, are self-evident truths of reason; that is, they are truths of a priori, affirmation and assumption. They are never arrived at by reasoning, or by induction, and never can be. The mind only knows them by virtue of its own laws, and directly assumes and intuits them, whenever they are suggested. The eye of reason sees them as distinctly as the mind sees objects of vision presented to the fleshly organ of vision. The mind is so constructed that it sees some things with the natural fleshly eye, and some truths it sees directly with its own eye without the use of an eye of flesh. All the self-evident truths of reason belong to this class; that is, they are truths which the mind sees and knows, and does not merely believe. In reasoning, the bare statement of a self-evident truth is enough, provided, as has been said, that it is so perspicuously stated that the terms of the proposition are understood. It should be borne in mind, in reasoning, that all men have minds, and that the laws of knowledge are physical, and, of course, fixed, and common to all men. The conditions of knowledge are in all men the same. We are therefore always to assume that self-evident truths can not but be known, so soon as they are stated with such perspicuity as that the terms in which they are expressed are understood. Our future inquiries will present many illustrations of the truth of these remarks.

It should be also remarked that universality is an attribute of the self-evident truths of reason. That is, they are

universal in the sense,

(1.) That all men affirm them to be true when they understand them; and,

(2.) They all affirm them to be true in the same way; that is, by direct intuition, or they perceive them in their own light, and not through the medium of reasoning, demonstration, or sense; and,

(3.) Self-evident truths of reason are true without exception, and in this sense also universal.

(4.) Necessity is also an attribute of self-evident truths. That is, they are necessarily true, and cannot but be so regarded. And when the conditions which have been named are fulfilled, they can not but be so known to every moral agent.

Self-evident truths of reason may be again divided into truths merely self-evident, and first-truths of reason. This class of truths possess all the characteristics of self-evident

truths, to wit: they are universal truths; they are necessary truths; they are truths of direct intuition; they are truths of certain knowledge.

Their peculiarity is this: they are truths that are necessarily and universally known by moral agents. That is, they are not distinguished from mere self-evident truths of reason, except by the fact that from the laws of moral agency they are known universally, and all moral agents do and must possess certain knowledge of them.

They are truths of necessary and universal assumption. Whether they are, at all times, or at any time, directly thought of, or made the particular object of the mind's attention or not, they are nevertheless at all times assumed by a law of universal necessity. Suppose, for example, that the law of causality should not be, at all times or at any time, a subject of distinct thought and attention. Suppose that the proposition in words, should never be in the mind, that "every event must have a cause." Still the truth is there, in the form of absolute knowledge, a necessary assumption, an a priori affirmation, and the mind has so firm a hold of it as to be utterly unable to overlook, or forget, or practically deny it. Every mind has it as a certain knowledge, long before it can understand the language in which it is expressed, and no statement or evidence whatever can give the mind any firmer conviction of its truth, than it had from necessity at first. This is true of all the truths of this class. They are always and necessarily assumed by all moral agents, whether distinctly thought of or not. And for the most part this class of truths are assumed without being frequently, or at least, without being generally the abject of thought or direct attention. The mind assumes them without a direct consciousness of the assumption.

For example, we act every moment, and judge, and reason, and believe, upon the assumption that every event must have a cause, and yet we are not conscious of thinking of this truth, nor that we assume it until something calls the attention to it. First-truths of reason, then, let it be distinctly remembered, are always and necessarily assumed, though they may be seldom thought of. They are universally known before the words are understood by which they may be expressed, and although they may never be expressed in a formal proposition, yet the mind has as certain a knowledge of them as it has of its own existence.

But it is proper to inquire whether there are any conditions of this assumption, and if so, what they are? Does the intelligence make this assumption upon certain conditions, or independent of all or any conditions? The true answer to this inquiry is, that the mind makes the assumption only upon the fulfillment of certain conditions. These conditions being fulfilled, the intelligence instantly and necessarily makes the assumption by a law of its own nature, and makes it whether the assumption be a distinct object of con

sciousness or not.

The only condition of this assumption that needs to be mentioned, is the perception of that by the mind to which the first truth sustains the relation of a logical antecedent or of a logical condition. For example, to develop and necessitate the assumption that every event must have a cause, the mind only needs to perceive or to have the conception of an event, whereupon the assumption in question instantly follows by a law of the intelligence. This assumption is not a logical deduction from any premise whatever, but upon the perception of an event, or upon the mind's having the idea or notion of an event, the intelligence irresistably, by virtue of its own laws, assumes the first-truth of causality as the logical and necessary condition of the event: that is, it assumes that an event and every event must have a cause.

The condition upon which the first-truths of reason are assumed or developed, is called the chronological condition of their development, because it is prior in time and in the order of nature to their development. The mind perceives an event. It thereupon assumes the first-truth of causality. It perceives body, and thereupon assumes the first-truth, space is, and must be. It perceives succession, and necessarily assumes that time is, and must be. These first-truths, let it be repeated, are not assumed in the form of a proposition, thought of or expressed in words, nor is the mind at the time always, or perhaps ever, at first, distinctly conscious of the assumption, yet the truth is from that moment within the mind's inalienable possession, and must forever after be recognized in all the practical judgments of the mind.

Thus, it should be distinctly said, do the first-truths of reason lie so deep in the mind as perhaps seldom to appear directly on the field of conscious thought, and yet so absolutely does the mind know them, that it can no more forget, or overlook, or practically deny them, than it can forget, or overlook, or in practice deny its own existence.

I have said that all reasoning proceeds upon the assumption of these truths. It must do so of necessity. It is preposterous to attempt to prove first-truths to a moral agent: for if a moral agent, he must absolutely know them already, and if he did not, in no possible way could he be put in possession of them except by presenting to his perception the chronological condition of their development, and in no case could any thing else be needed, for upon the occurrence of this perception, the assumption or development follows by a law of absolute and universal necessity. And until these truths are actually developed, no being can be a moral agent.

There is no reasoning with one who calls in question the first-truths of reason, and demands proof of them. All reasoning must, from the nature of mind and the laws of reasoning, assume the first-truths of reason as certain, and admitted, and as the a priori condition of all logical deductions and demonstrations. Some one of these must be assumed as true, directly or indirectly, in every syllogism and in every demonstration.

In all our future investigations in the line of truth we shall pursue, we shall have abundant occasions for the application and illustration of what has now been said of firsttruths of reason. If, at any stage of our progress, we light upon a truth of this class, let it be borne in mind that the nature of the truth is the preclusion, or as lawyers would express it, the estopple of all controversy.

To deny the reality of this class of truths, is to deny the validity of our most perfect knowledge and of course it is a denial of the validity of our faculties. The only question to be settled in respect to this class of truths, is, does the truth in question belong to this class? There are many of this class that have not been generally recognized as belonging to it. Of this we shall have abundant instances fall in our way as we proceed in our investigations. There are many truths which men, all sane men, certainly know, of which they not only seldom think, but which, in theory, they strenuously deny.

Before I dismiss this branch of our subject, I will mention some of the many truths that undeniably belong to this class, leaving others to be mentioned as we proceed and fall in with them in future investigations.

I have already noticed three of this class, to wit; the truth of causality-the existence of space and of time. That the whole of any thing is equal to all its parts, is also a truth