Introduction. This article focuses on the specifics of the arguments from ignorance and arguments from silence. The relevance of the work is due to the growing interest of the scientific community in modeling of defeasible (presumptive) reasoning and verification of their validity.

Methodology and sources. Methodologically, the work is based on the dialectical approach of D. Walton, who proposed a corpus of argumentation schemes for presumptive arguments and a methodology for testing their validity using critical questions. To test the validity of arguments from ignorance and silence, we propose the concept of epistemic burden, the proper fulfillment of which is a necessary condition for the validity of these arguments.

Results and discussion. The result of the research is the development of corpuses of critical questions for two schemes of argumentation: the argument for ignorance and the argument from silence, which include questions to check the fulfillment of the epistemic burden by the proponent or information source. The methodology for verifying arguments using the proposed critical questions is analyzed using examples.

Conclusion. The difference between the two types of reasoning is that in the argument from ignorance, the epistemic burden is placed on the discussion participants (panelists), and in the argument from silence it is placed on the source of the information.