This is the 12968th most frequent Russian word.
личности
"Личности" means "personalities" or "individuals" in English.
Here, 'личности' refers to 'personalities', indicating the individual characters of great scientists.
Личности великих ученых оставили след в истории.
The personalities of great scientists left a mark on history.
In this sentence, 'личности' denotes 'personality', emphasizing individual personal growth.
Развитие личности важно для каждого человека.
The development of personality is important for each person.
This instance uses 'личности' to mean 'individuals' indicating famous or notable people.