The main subjective factors that make an influence on the content of decisions of the only one body of constitutional jurisdiction in Ukraine are analysed in the article on the basis of Ukrainian and international practice of constitutional justice. It is noted that the scope of judicial discretion in the constitutional justice is significantly limited by the principles of law, recognized and valid in a democratic society, as well as by the general legal concepts. It is emphasized that from a psychological point of view, the process of reasoning in the constitutional justice is to produce reasons and counterargumentation in the discourse (primarily in imaginary dialogue), focusing on the specific wording of the legal reasoning of the Constitutional Court, which requires compliance with at least some very important rules.