Page images

mately connected with it, as to be a part of that study. Hence, therefore, the great importance of physiological studies to youth, and the systematic enforcement of the great truths of the science. But there is another very powerful argument for the introduction of physiology into the modern plans of education; and that is the tendency it has to give the pupil an enlarged knowledge of the diversified works, beneficence, and wisdom of God in the creation of man. The pupil will soon learn that the Creator has bestowed on the body and on the mind, and on external nature, determinate constitutions, and arranged them so as to act on each other, and to produce happiness or misery to man according to certain definite principles and arrangements. Thus it is that physiology becomes in a degree a religious study.

Of what does the science of physiology treat? Of the functions and properties of living bodies. What is meant by a living body? That which by a certain organized structure is enabled to live and propagate the kind. What is the meaning of an organ as employed in this science? A whole consisting of various parts necessary to produce a certain effect. What bodies are subjects of physiology? Animals and vegetables. Do you know what life is? No. But do we know what life does? Very well. What does life counteract? The laws of gravity. If the fluids of our bodies followed the natural tendencies of fluids, what would happen? They would descend to our feet when we stood, or to our backs when we lie. What is the reason they do not? The cause may be referred to the action of the heart and vessels, and we derive that power from life. Does life resist the effects of mechanical powers? Yes. Give examples. Friction will thin and wear away a dead body, but is actually the cause of thickening a

living one. What does life prevent? Life prevents chemical agency; a body when left to itself soon begins to putrefy, but this never happens during life. What does life modify? The power of heat beneath a tropical sun, or within the arctic circle the temperature of the human body remains unaltered when examined by a thermometer. Is life the cause of the constant changes that are going forward in our bodies? Yes. What do you term that substance which covers every part of the surface of the body? The integuments constitute what is termed the hide in various animals. Into how many parts is it divided? It consists of three, the scarf-skin and mucous net-work, and the real skin. What does the true skin constitute? It constitutes the organ of touch. Where does this power exist in the greatest degree? At the ends of the fingers. How do most animals possess the sense of touch? In the nose or snout; and in the elephant, the trunk is provided with an organ as small and delicate as the human finger. What animals have exceeding thick scarf-skin? The elephant and hippopotamus. What do the bones form? The foundation of the body, the basis for the softer parts. What does the skull or cranium contain? The brain. Where is it fixed? At the top of the vertebral column or bones of the back. What is in the centre of these bones? A hollow space for the spinal marrow. What commences at a little distance from the skull? The ribs. How are they all fixed? To the bones of the back and to the breast. What does their curvature form? A cavity which is called the chest, and contains the heart and lungs. What bony structure have we at the lower part of the vertebral column? The hips. What have we at the upper part of the ribs? The shoulder-blade. Of what description are the joints that compose the shoulder and the hip? They are called in mechanics, the uni

versal joint, or the ball and socket. What are the ends of bones covered with? A gristly substance called cartilage.


Logic may be defined to be, that art or branch of knowledge which has for its object the investigation of truth, and the best method of communicating it to others; or in other words, the art of employing our rational faculties in the best manner in searching after truth and duty on any subject.

Human knowledge may be classed under three heads, viz. Physics, Ethics, and Logic. The first has for its object the nature and laws of the natural world, and is sometimes denominated experimental philosophy; the second lays down rules for the regulations of life, and points out the best means for promoting human happiness, hence it is called moral philosophy; the last teaches the right use of reason in the investigation of truth, and has been denominated rational philosophy. A complete system of logic comprehends the following subjects:

1. The analysis of the faculties of the human mind. 2. The manner of applying the faculties in the investigation of truth.

3. The method of communicating those investigations, so as to make them useful to others.

The study of the mind in the most general sense is called Pneumatology or Metaphysics, including all the knowledge we can acquire of mind, whether of God, of intermediate spirits, or of man considered as an intelligent being.

The two first are properly the subjects of natural theology, the latter belongs to logic. In the 1st division of the course it is proposed shortly to treat of the faculties of the mind in the following order :

1. Sensation and Perception; 2. Attention; 3. Consciousness; 4. Conception; 5. Association; 6. Memory; 7. Abstraction; 8. Judgment; 9. Imagination; 10. Reason; 11. Taste; 12. The moral faculty.

By the term faculties or powers of the mind, we are not to understand separate and independent energies or principles which may be supposed to unite in forming the mind; but merely different modes of action of the same thinking principle. When the mind is employed or engaged about that which is present, or present objects, we say it is exercising the faculty of perception; and when engaged about that which is past, the faculty of memory; still it is the same principle only directed to different objects. By an analysis of the faculties or powers of the mind, is meant an attempt to discover the order in which certain operations of the mind succeed one another, or to investigate the laws of human thought. These laws are merely a collection of general truths, the result of reflection, and have received the name of laws for the same reason that gravitation is called a law in the material world.

What is logic? That art which investigates the principles on which reasoning is conducted, and furnishes rules to secure the mind from error in its deductions. Is logic also a science? It is strictly a science when it institutes an analysis of the process of the mind in reasoning. Why has so much censure been heaped upon logic? Because the true nature and object of it being utterly mistaken, it was involved in a mist of words, to the exclusion of all sound philosophical investigation. On what ground is logic still objected to ? On the ground that it professes to furnish a peculiar method of reasoning. Is that objection true? No; logical reasoning is a form to which all correct reasoning may be ultimately reduced, and a test by which the validity of every argument may

be tried. What is then the appropriate province of logic? Its appropriate province is to preclude the possibility of any error creeping in between the principles or grounds from which we are arguing and the conclusions we deduce from them. To what branch of knowledge is logic applicable? To every branch alike; its application is as boundless as human knowledge itself, since there is no subject on which reasoning is not employed and to which consequently logic may not be applied. What is the general error on this point? Because it is applicable to everything, to consider everything as its proper province. You said that logic is a test by which the validity of every argument may be tried; now what is an argument? An argument is an expression, in which from some principle laid down as granted another principle is deduced. What is an argument logically speaking? A logical argument consists of two grounds called premises, and the inference drawn from these premises called a conclusion. What is an argument stated at full length and in its regular form called? A syllogism. Give an instance of a proper syllogism.

No wicked man is happy;

Every tyrant is a wicked man; therefore
No tyrant is happy.

Is the conclusion of a syllogism inevitable whatever terms the premises may stand for? Yes, because a syllogism is an argument so expressed that the conclusiveness of it is manifest without considering the meaning of the terms. Give me an example. Y is X, Z iz Y, therefore Z is X; this conclusion is inevitable whatever we may substitute for these symbols. Can all legitimate arguments be ultimately brought to this form? Certainly. How many terms or logical divisions are there in a syllogism? Three; the middle term, and the

« PreviousContinue »