An ens rationis is something whose being consists in the possibility of something being true about something else.
An ens rationis may be defined as a subject whose being consists in a Secondness, or fact, concerning something else. Its being is thus of the nature of Thirdness, or thought. Any abstraction, such as Truth or Justice, is an ens rationis. That does not prevent Truth and Justice from being real powers in the world without any figure of speech.