The life of the mind, although supremely excellent in itself, can not bring health into the life of instinct ...it is, as a rule, too widely separated from instinct... to afford either a vehicle for instinct, or a means of subtilizing and refining it. Thought is in its essence impersonal and detached, instinct is in its essence personal and tied to particular circumstances: between the two, unless both reach a high level, there is a war which is not easily appeased. ...Thought which does not rise above what is personal is not thought in any true sense: it is merely a more or less intelligent use of instinct. It is thought and spirit that raise man above the level of the brutes. ...Thought must achieve its full growth before a reconciliation with instinct is attempted. ... When refined thought and unrefined instinct coexist, as they do in many intellectual men, the result is a complete disbelief in any important good to be achieved by the help of instinct. According to their disposition, some such men will as far as possible discard instinct and become ascetic, while others will accept it as a necessity, leaving it degraded and separated from all that is really important in their lives. Either of these courses prevents instinct from remaining vital, or from being a bond with others; either produces a sense of physical solitude... so long as this sense of unity is absent, instinct and spirit cannot be in harmony, nor can the life of the community have vigor... The life of the mind, because of its detachment, tends to separate a man inwardly from other men, so long as it is not balanced by the life of the spirit. For this reason, mind without spirit can render instinct corrupt or atrophied... On this ground, some men are hostile to thought. But no good purpose is served by trying to prevent the growth of thought, which has its own insistence, and if checked in the directions in which it tends naturally, will turn into other directions where it is more harmful. ...But the opposition is not irreconciliable: all that is necessary is that both thought and instinct should be informed by the life of the spirit. ... In order that human life should have vigor, it is necessary for the instinctive impulses to be strong and direct; but in order that human life should be good, these impulses must be dominated and controlled by desires less personal and ruthless, less liable to lead to conflict than those that are inspired by instinct alone. Something impersonal and universal is needed over and above what springs out of the principle of individual growth. It is this that is given by the life of the spirit. ... The life of the spirit demands readiness for renunciation when the occasion arises, but is in its essence as positive and as capable of enriching individual existence as mind and instinct are. It brings with it the joy of vision, of the mystery and profundity of the world, of the contemplation of life, and above all the joy of universal love. It liberates those who have it from the prison-house of insistent personal passion and mundane cares. It gives freedom and breadth and beauty to men's thoughts and feelings, and to all their relations with others. It brings the solution of doubts, the end of the feeling that all is vanity. It restores harmony between mind and instinct, and leads the separated unit back into his place in the life of mankind. For those who have once entered the world of thought, it is only through spirit that happiness and peace can return.

What It Means

This is a placeholder explanation generated by the low-overhead model. It interprets "The life of the mind, although supremely excellent in itself, can not bring health into the life of instinct ...it is, as a rule, too widely separated from instinct... to afford either a vehicle for instinct, or a means of subtilizing and refining it. Thought is in its essence impersonal and detached, instinct is in its essence personal and tied to particular circumstances: between the two, unless both reach a high level, there is a war which is not easily appeased. ...Thought which does not rise above what is personal is not thought in any true sense: it is merely a more or less intelligent use of instinct. It is thought and spirit that raise man above the level of the brutes. ...Thought must achieve its full growth before a reconciliation with instinct is attempted. ... When refined thought and unrefined instinct coexist, as they do in many intellectual men, the result is a complete disbelief in any important good to be achieved by the help of instinct. According to their disposition, some such men will as far as possible discard instinct and become ascetic, while others will accept it as a necessity, leaving it degraded and separated from all that is really important in their lives. Either of these courses prevents instinct from remaining vital, or from being a bond with others; either produces a sense of physical solitude... so long as this sense of unity is absent, instinct and spirit cannot be in harmony, nor can the life of the community have vigor... The life of the mind, because of its detachment, tends to separate a man inwardly from other men, so long as it is not balanced by the life of the spirit. For this reason, mind without spirit can render instinct corrupt or atrophied... On this ground, some men are hostile to thought. But no good purpose is served by trying to prevent the growth of thought, which has its own insistence, and if checked in the directions in which it tends naturally, will turn into other directions where it is more harmful. ...But the opposition is not irreconciliable: all that is necessary is that both thought and instinct should be informed by the life of the spirit. ... In order that human life should have vigor, it is necessary for the instinctive impulses to be strong and direct; but in order that human life should be good, these impulses must be dominated and controlled by desires less personal and ruthless, less liable to lead to conflict than those that are inspired by instinct alone. Something impersonal and universal is needed over and above what springs out of the principle of individual growth. It is this that is given by the life of the spirit. ... The life of the spirit demands readiness for renunciation when the occasion arises, but is in its essence as positive and as capable of enriching individual existence as mind and instinct are. It brings with it the joy of vision, of the mystery and profundity of the world, of the contemplation of life, and above all the joy of universal love. It liberates those who have it from the prison-house of insistent personal passion and mundane cares. It gives freedom and breadth and beauty to men's thoughts and feelings, and to all their relations with others. It brings the solution of doubts, the end of the feeling that all is vanity. It restores harmony between mind and instinct, and leads the separated unit back into his place in the life of mankind. For those who have once entered the world of thought, it is only through spirit that happiness and peace can return." in the context of "Bertrand Russell, Why Men Fight: A Method of Abolishing the International Duel (1917)" to mean that wisdom is timeless.