Sense of Life
Sense of Life is a phrase that is used most frequently in Objectivist esthetics, but like many other esthetic concepts, has its roots in epistemology.
A Sense of Life is an emotional evaluation of the world. It is subconsciously formed through a process of emotional integration. It integrates one's emotions and value-judgments. Since it is an automatic process, it begins with one's first emotional judgments about the world long before the capacity to rationally judge the world has been achieved. It is because of this that one's Sense of Life can differ radically from one's explicit metaphysical view. Although the two relate, and affect one another, there is no causal connection.
A Sense of Life differs from simple emotions. It is not an emotional evaluation of one's metaphysical views, whether implicit or explicit. A Sense of Life is not programmed by a single evaluation. It is an integration of countless evaluations. Over the course of one's life, it integrates emotions and value-judgments related to all aspects of living. A Sense of Life is the sum of these emotions and value-judgments. This is the method by which it acts as an emotional evaluation of the world. Not directly through a concept of the world and an appropriate judgment, but a complex summation of judgments about every aspect of the world one has made.
Sense of Life is like an emotional worldview. It doesn't convey what the world is like, but it does convey how you feel about it. It's an emotional basis for judging the world. If someone had a negative Sense of Life, they might always look for some hidden cost, or look every gift horse in the mouth. They might fear the worst, and when good things happen, they might not really believe it. Remember that this does not necessarily reflect their explicit philosophy. It's just the way they feel about the world.
Sense of Life is important in the field of esthetics because it helps us answer why it is people respond the way they do to a piece of art. The art itself doesn't create an emotional reaction. A piece of art could convey a happy view of the world, for instance. But depending on whether that view resonates with the viewer, it may not create the same emotion. Someone who's sense of life agrees with the view may feel happiness, but other's might feel fear, hatred, sorrow, or anything else. The reactions are based on how the viewer's Sense of Life reacts with the view of the world being conveyed.
You can see how the artist's metaphysical value-judgments would have a particularly strong reaction with a viewer's Sense of Life. If the viewer's emotional view of the world conflicts with the metaphysical value-judgments being conveyed, they may be left repulsed by the work. If the two align well, they may be attracted to it.
In this way, art can fulfill a larger purpose for the viewer. It has the ability to act as a confirmation of his view of existence, or a denial of it. When it confirms his view, he can feel that his own view of the world is essentially correct, and feel a confidence that comes from knowing that he's properly identified the world.
If the view of existence clashes with the work of art, it can be taken as an attack on the efficacy of his mind. He'll feel that his own worldview, or the emotional equivalent, is being challenged. And in turn, that appears as a challenge to the effectiveness of his mind, since it was his mind that came to that view of the world.