Nikolai Berdjaev describes many theoretical and practical dilemmas of sex in his paradox of sex ontology, his paradox of sex knowledge and his paradox of sexual behaviors and energy.

• 别尔加耶夫以其个性理论为基石，以悖论的方式表达出在性之中存在的诸多理论困境与现实困境，即性本体悖论、性知识悖论、性行为悖论及性能量悖论。