Chapter 4 of Book 4

The Nature of Science

by Socrates Icon

The same principle holds in the sciences. The object of science is knowledge. But the object of a particular science is a particular kind of knowledge.

The science of house-building is a kind of knowledge different from other kinds. It is therefore called “architecture” because it has a particular quality which no other has. It has this particular quality because it has a particular object. This is true of the other arts and sciences.


Regarding relatives, if one word of a relation is taken alone, then the other is taken alone. If one term is qualified, the other is also qualified. But I do not mean to say:

  • that relatives may not be disparate, or
  • that the science of health is healthy, or
  • that the science of disease is necessarily diseased, or
  • that the sciences of good and evil are therefore good and evil

I only mean that the word “science” is no longer used absolutely. Instead, it has a qualified object which in this case is the nature of health and disease. It becomes the “science of medicine” and not merely as “science”.

Thirst is one of these essentially relative terms, having a relation to drink. A certain kind of thirst is relative to a certain kind of drink. But thirst taken alone is neither of much nor little, nor of good nor bad, nor of any particular kind of drink, but of drink only. Thus, a thirsty soul desires only drink.

If something pulls a thirsty soul away from drink, then that something must be different from the thirst. A man might be thirsty but be unwilling to drink. A weaker part of his soul from passion is bidding a man to drink, and a stronger part from reason forbidding him.


These 2 are different from one another.

  • The one with which a man reasons, we may call the “rational principle of the soul”.
  • The other, which drives him to love, hunger, thirst, and feel the flutterings of any other desire, can be called the “irrational” or appetitive.
    • It is the ally of sundry pleasures and satisfactions. Passion or spirit is akin to desire.

Thus, the soul has 2 principles.

Leontius was the son of Aglaion. He came one day from the Piraeus, under the north wall on the outside. He heard of dead bodies at the place of execution. He wanted to see them, yet also dreaded and abhorred them. For a time, he struggled and covered his eyes. But finally, the desire got the better of him. He forced them open and ran up to the dead bodies, saying, “Look ye wretches, take your fill of the fair sight”.

The moral of the tale is, that anger at times goes to war with desire, as though they were two distinct things.


There are few cases when a man’s desires violently prevail over his reason. In those cases, he reviles himself and is angry at the violence within him. This struggle is like the struggle of factions in a State. In this struggle, his spirit is on the side of his reason.

But no one has observed the passionate or spirited element join the desires when reason rules over them.

If a noble man has injured another, he will be less indignant in receiving physical suffering from the injured person in return. His anger is not excited by such suffering. But when a noble is injured, he gets angry. His suffering makes him determined at revenge. It makes him believe to be on the side of justice. His noble spirit will not be quelled until his reason-shepherd bids his passion-dog stop barking.

Glaucon So in our State, the auxiliaries are the dogs and the rulers are their shepherds.

Passion or spirit appeared initially to be a kind of desire. But now they are quite the contrary.

In the conflict of the soul, spirit is on the side of the rational principle. Does it mean that passion is different from reason? This is consistent with:

  • our State being composed of three classes= traders, auxiliaries, counsellors.
  • being different from desire and reason.

Or is passion a kind of reason? In this case, the soul will have two principles, the rational and the lustful, instead of three.

Passion is suppposed to be the natural auxiliary of reason when reason is corrupted by bad education.

Glaucon Passion is different from reason as proven by young children being full of spirit as soon as they are born. Some children never attain to the use of reason. Most of them acquire it later.
Socrates Excellent. Passion is equally seen in animals. Homer writes:
"He smote his breast, and thus rebuked his soul."

Homer clearly shows that reason is different from the unreasoning anger which is rebuked by it. And so, we have agreed that:

  • the same virtues which exist in the State exist also in the individual, and
  • that they are three in number= wisdom, courage, temperance.

We must infer that the individual and State is wise in the same way.


The same quality which constitutes courage in the State constitutes courage in the individual. Both the State and the individual bear the same relation to all the other virtues. The individual is just in the same way that the State is just.

The justice of the State consisted in each of the three classes doing the work of its own class. The individual in whom the several qualities of his nature do their own work will be just, and will do his own work. The rational principle is wisdom.


It has the care of the whole soul. It should rule.

The passionate or spirited principle is its subject and ally. The united influence of music and gymnastics will bring reason and passion into accord by:

  • nerving and sustaining the reason with noble words and lessons,
  • moderating and soothing and civilizing the wildness of passion by harmony and rhythm.

When reason and passion are nurtured, educated, and have truly learned their own functions, will rule over the concupiscent. In each of us, this is the largest part of the soul and by nature most insatiable of gain.

They will keep guard of this lest the bodily pleasures empower the concupiscent soul and enslaves those who are not her natural-born subjects and overturn one’s whole life. They together will be the best defenders of the whole soul and body against external attacks.


Reason counsels and passion fights, executing the commands and counsels or reason.

A courageous person is one whose spirit retains the commands of reason on what he should fear or not fear. A wise person is one who has reason with the knowledge of what is for the interest of desire, reason, and passion. A temperate person is one who has these three elements in friendly harmony and has reason as the ruling principle for desire and passion. We have explained again and again how and by virtue of what quality a man will be just.

Is justice dimmer and different in the individual than in the State?


A few common instances shows that they are different. A just state:

  • avoids stealing money in the same way that a just man does
  • avoids treachery to other states in the same way that a just citizen avoids it to his friends
  • never breaks faith in oaths or agreements in the same way that a just citizen keeps his oaths.

Then our dream has been realized. In the beginning, we suspected that some divine power conducted us to a primary form of justice. We have now verified it.

The division of labour which required the carpenter, the shoemaker, and the rest of the citizens to be doing each his own business, and not another’s, was a shadow of justice. But in reality, justice was concerned not with the outward man, but with the inward or the true self. [svadharma]

The just man does not permit the several elements within him to interfere with one another, or any of them to do the work of others. He sets his own inner life in order. He masters himself with his own law, to be at peace with himself.


The 3 principles of animal-desire, passion, and reason may be compared to the higher, lower, and middle notes of the scale and the intermediate intervals.

When he has bound together these notes and intervals, they are no longer many. They become one, entirely temperate and perfectly adjusted nature.

He then proceeds to act in law, medicine, politics or private business. He calls:

  • “just and good action” if they are from knowledge and wisdom
  • “unjust action” if they impair this knowledge and wisdom
  • “ignorance” the opinion which presides over the unjust action.



Injustice is a strife between the three principles which leads to the vices of intemperance, cowardice, and ignorance. It begins when one principle rebels against the others, causing the confusion and delusion of injustice.

Justice and injustice are like health and disease. These lie in the soul just as health and disease lie in the body.

  • Healthy things cause health.
  • Unhealthy things cause disease.
  • Just actions cause justice.
  • Unjust actions cause injustice.
  • The creation of health is the institution of a natural order of one by another in the parts of the body.
  • The creation of disease is the production of a state of things at variance with this natural order.
  • The creation of justice is the institution of a natural order and government of one by another in the parts of the soul.

When things go against the natural order of things, injustice [adharma] is created. This means that:

  • virtue is the health, beauty, and well-being of the soul
  • vice is its disease, weakness, and deformity.
  • good practices lead to virtue
  • evil practices lead to vice.

Is it more profitable to act justly whether seen or unseen, or to act unjustly as long as it is unseen and unpunished?

Glaucon This question is ridiculous. When the body is gone, it does not matter whether the soul is pampered with meat, drink, wealth, and power.

From above, we might see that virtue is one, but vices are many and are of four kinds, just as there are five types of the State and five types of the soul. The just state has two names:

  • Monarchy - This is rule exercised by one distinguished man
  • Aristocracy - This is rule exercised by distinguished men.

Latest Articles

How to Fix Ukraine
How to Fix Ukraine
The Age of the Universe
The Age of the Universe
Material Superphysics
The End of Capitalism (and Marxism)
The End of Capitalism (and Marxism)
The Elastic Theory of Gravity
The Elastic Theory of Gravity
Material Superphysics

Latest Simplifications

Nova Organum by Francis Bacon
Nova Organum by Francis Bacon
The Analects by Confucius
The Analects by Confucius
The Quran by The Prophet Mohammad
The Quran by The Prophet Mohammad

All Superphysics principles in our books

The Simplified Series

Developing a new science and the systems that use that science isn't easy. Please help Superphysics develop its theories and systems faster by donating via GCash