By applying dialectical materialism, as opposed to metaphysics and idealism.

The 3 major assertions of idealism are as follows:

1. Idealism asserts that the material world is dependent on the spiritual
2. Idealism asserts that spirit, or mind, or idea, can and does exist in separation from matter. (The most extreme form of this assertion is subjective idealism, which asserts that matter does not exist at all but is pure illusion.)
3. Idealism asserts that there exists a realm of the mysterious and unknowable, "above," or "beyond," or "behind" what can be ascertained and known by perception, experience, and science.

The 3 basic teachings of materialism as counterposed to idealism are:

1. Materialism teaches that the world is by its very nature material, that everything which exists comes into being on the basis of material causes, arises and develops in accordance with the laws of motion of matter.
2. Materialism teaches that matter is objective reality existing outside and independent of the mind; and that far from the mental existing in separation from the material, everything mental or spiritual is a product of material processes.
3. Materialism teaches that the world and its laws are fully knowable, and that while much may not be known there is nothing which is by nature unknowable.

Mechanistic materialism makes certain dogmatic assumptions:

1. That the world consists of permanent and stable things or particles, with definite, fixed properties;
2. That the particles of matter are by nature inert and no change ever happens except by the action of some external cause;
3. That all motion, all change can be reduced to the mechanical interaction of the separate particles of matter;
4. That each particle has its own fixed nature independent of everything else, and that the relationships between separate things are merely external relationships.

Dialectical materialism holds instead:

1. The world is not a complex of things but of processes;
2. That matter is inseperable from motion;
3. That the motion of matter comprehends an infinite diversity of forms which arise one from another and pass into one another;
4. That things exist not as separate individual units but in essential relation and interconnection.

Putting it all together, we get the following:

1. Dialectical materialism understands the world, not as a complex of ready-made things, but as a complex of processes, in which all things go through an uninterrupted change of coming into being and passing away.

2. Dialectical materialism considers that matter is always in motion, that motion is the mode of existence of matter, so that there can no more be matter without motion than motion without matter. Motion does not have to be impressed upon matter by some outside force, but above all it is necessary to look for the inner impulses of development, the self-motion, inherent in all processes.

3. Dialectical materialism understands the motion of matter as comprehending all changes and processes in the universe, from mere changes of place right to thinking. It recognizes, therefore, the infinite diversity of the forms of motion of matter from the simple to the complex, from the lower to the higher.

4. Dialectical materialism considers that, in the manifold processes taking place in the universe, things come into being, change and pass out of being, not as separate individual units, but in essential relation and interconnection, so that they cannot be understood each separately and by itself but only in their relation and interconnection.

Karl Marx created dialectical materialism by turning Hegel's idealist dialectic into a materialist one. Then, he applied it to the progression of society, creating historical matetialism. By analyzing social structures and progress as a dialectical process based in materialism, we can learn from history and analyze where it's going. This is scientific socialism in progress.