The paper is devoted to revealing the reasons for the lacunarity in forming names of persons from adjectives denoting mental characteristics of a human. The property of a lexical unit to have one or another set of derivatives depends on restrictions affecting the possibility of linking derivational
morphemes to a stem of a derivational base. The objective of the present paper is to determine which formal restrictions on the combinability of morphemes stipulate the lacunarity of the derivational paradigms of adjectives. With the availability of a diversity complex of wordbuilding formants used in forming an adjective-based name, the author determines (a) which stems are capable of combining with several appropriate affixes (b) which stems combine only
with one of a number of synonymous word-formative devices (c) which stems are not used with any of the presented suffixes.