The content of the empirical description is expressed by certain sensual images and ideas for the object under investigation, and the theoretical of certain concepts, categories, judgments, conclusions. At this level, the historian uses three types of concepts and categories:



![Declaration_independence.jpg](https://cdn.steemitimages.com/DQmWEdGrCbPXTKksHsfp3oDKs7vPH39RcsevAb6ZYAtg9sn/Declaration_independence.jpg)
[image source](https://www.vox.com/2015/8/13/9148929/inaccurate-art-history)

- general-philosophical concepts and categories such as: relationship, interaction, condition, environment, cause and effect, etc.
- private-philosophical concepts / philosophical-historical / like: base, superstructure, social structure, state, class, class, challenge, etc.
- special scientific concepts or historically valid only for certain periods of the development of society such as: manufactory, etc.


The ultimate form of expression, not the knowledge of the empirical level of historical knowledge, is the historical description and the theoretical historical explanation. They are conditionally given consistently and conditionally differentiated. As a logical procedure, each explanation contains two components, namely the explandum, the set of situations describing the phenomenon to be explained and the explane - the set of explanatory statements. In this connection, two types of knowledge are used in each scientific explanation: first, this is the knowledge of the objective reality that is obtained at the empirical level of its study and which is expressed in its description. In history this knowledge is known as source knowledge. 

Secondly, all other knowledge is about both the studied reality and the scientific picture of the world, and in particular the knowledge that forms the world scientific picture. In history, this second type of knowledge is called the term outside of the source of knowledge. Without it it is impossible to explain the studied events and processes. Historical epistemology offers different options for the classification of historical explanations by separating such basic types: explanation by law, causal or causal explanations, genetic, structurally functional. The most fundamental are the explanations by law. The whole thing, however, is in how much the existence of laws in history is recognized, the second question in these explanations is what these laws see, ie. in which sphere of public reality are considered the most fundamental.


Widespread have causal explanations. They are used to reveal the interrelationship and conditionality of simultaneous or sequential historical phenomena. This type of explanation should take into account another category, namely environment (s), since the cause does not occur in a sterile environment but always occurs under certain conditions that may stimulate or restrict it and sometimes make it impossible . In this sense, the nature of the outcome depends not only on the nature of the cause. But of the conditions in which the cause has occurred.