J.J. Rousseau boiled this question down to the question of social inequality and the ways to overcome it. Kant believed in the basic question of philosophy, gets down to the “apriori” knowledge, i.e., the knowledge that is produced by questioning, and J.G. Fichte believed this is a question of the fundamental principle of all knowledge.
The well-known Russian philosopher S.L. Frank was often pre-occupied with a question: what is the man and what is its true purpose, which a well-known representative of the French existentialist Albert Camus believed was served as the question of whether or not life is to be lived.
Idealists
As for the idealists, they recognize the primary idea, spirit and consciousness. They believe the body is the material product of the spiritual world. However, the relationship of consciousness and matter, representatives of the objective and subjective idealism is not understood the same way. Objective and subjective idealism – are two different opinions. If you read David Birnbaum Summa Metaphysica, you would know that the representatives of objective idealism (Plato, Leibniz, G.W.F. Hegel, and others.), recognizing the reality of the world, it is believed that in addition to the human consciousness there is a “world of ideas”, “global intelligence”, ie. something that identifies all material processes, which Jung called “collective consciousness”. In contrast to this view, representatives of subjective idealism (D. Berkeley, David Hume, Immanuel Kant, and others.) believed that the things that we see, feel and smell, are the combinations of our sensations. Consistent implementation of this view leads to solipsism,i.e. the recognition of really existing only knowing subject, which means people create their reality in their head.
Materialists
Materialists, on the other hand, defended the idea that the world is an objectively existing reality. Consciousness is considered a derivative, secondary to the matter. Materialists are in positions of materialist monism (from Greek “monos” – one). This means that only the beginning, the foundation of all things deemed to matter. Consciousness is considered to be a product of highly organized matter – the brain.
However, there are other philosophical views on the relationship of matter and consciousness. Some philosophers consider the matter and consciousness as two equivalent foundations of all things, independent of each other. Such views were attributed to Descartes, F. Voltaire, Newton and others. They are called dualists (from the Latin “dualism” – double) for recognition as equal matter and mind (spirit).
Materialists are based on the fact that the world is “knowable”, our knowledge of it, proven practices, able to be reliable, and provide the basis for an effective, purposeful activity of people.
Idealists, on the question of the “knowability” of the world were divided into two groups. Subjective idealists doubt that the knowledge of the objective world is possible, and the objective idealists, though they acknowledge the possibility of knowing the world, give it a human cognitive abilities in dependence on God or supernatural forces.
Philosophers who deny the possibility of knowing the world, called agnostics. Rebates agnosticism do representatives of subjective idealism, who doubt the possibilities of knowing the world or declare some areas actually fundamentally unknowable.
The existence of the two main trends in philosophy has a social base or sources and epistemological roots.
Social foundation of materialism can be considered the need for some sections of society to the organization and conduct of practical activities proceed from experience and build on the achievements of science, as well as its epistemological roots are the claims of the possibility of obtaining accurate knowledge of the phenomenon of the world.
The social foundations of idealism include underdevelopment of science and disbelief in its potential, lack of interest in its development and use of research results of certain social strata. By the epistemological roots of idealism – the complexity of the process of cognition, its contradictions, the possibility of the separation of our concepts of reality, elevating them into an absolute. Idealism developed in the history of philosophy, in close association with the religion. But philosophical idealism differs from religion that invests its evidence in the form of theorizing, and religion, as noted earlier, is based on the recognition of the indisputable authority of faith in God.