There are several sources of philosophical systems.
The most profound is the indian system named in the upanishads.
Which describes the inner meaning of lifequestions.

Other systems from greek to roman,
and from the enlightenment to modern day.

In the greek we know of plato and socrates.
Other names also were well known in that time,
for example, cicero, pythagoras, aristoteles and less known ones who didn't make it to currentday history books.

Philosophy is the science of giving life a name in all its parts.
For example, in this science the first methods of describing experience gave a place.

The greek system of philosphy was not based on equipment to compare and compute things that
were reducable to numbers or logics.

The roman system was the first inventing the method of counting and arithmetics.
the roman system gave way to the civilisation as current days are built on.
The method of giving someone the right of property was invented in that time.
As well as ways of governing regions in a empire.
governing in the name of democracy.

In the time around five hundred ago the enlightenment was the evolutionary step to wards the world of today.
famous persons like leonardo da vinci, mozart, and others.

the enlightenment which gave the individual person a right to have its own meaning,
and the birthrigth to have freedom of place in the world.

Current day philosophies are based on all the former systems.

In systems of philosophy science tries to give place to parts of reality.
Parts in reality that are based on words and their meaning.
The words; good bad,lifepurpose, how to speak, important values.
In the way of giving meaning to the central words and acts the values in a society gets form.

In the roman empire different values formed the laws and the governent than today.
In each era of civilisation a different value gives form to what is important.
Values that dictate laws, rules and obligation.
Values that give protection in different ways.
Values that add a place for religion, culture, economical system.