Question: Are awakened beings (觉者) like Buddhas (佛陀), Pratyekabuddhas (辟支佛), Bodhisattvas (菩提萨埵/菩萨) and Arhats (阿罗汉/罗汉) still considered as sentient beings?
Answer: The term ‘sentient beings’ (有情众生) or simply ‘beings’ (众生) is often used to refer to ordinary beings (凡夫) — who are not noble (i.e. awakened or enlightened) beings (圣者). If in this sense, noble beings are surely not merely sentient beings; not the usual sentient beings.
However, if ‘sentient beings’ is understood in the sense of beings who have and perceive feelings, awakened beings are great sentient beings, who have unleashed (or are unleashing) sentient beings’ highest spiritual potential. Other than meaning ‘Buddhas-to-be’, the term ‘Bodhisattvas’ means ‘awakened sentient beings’ (觉有情) and ‘those who awaken sentient beings’. The term ‘Buddhas’ means ‘(fully) awakened beings’ or ‘all-enlightened ones’.
Without sentience, it would be impossible for awakened beings to experience, embody and express these perfect pure emotions of the Four Immeasurable Minds (四无量心) to benefit other sentient beings — loving-kindness (慈), compassion (悲), rejoice (喜) and equanimity (舍). The difference between the sentience of ordinary beings and awakened beings is that the first have much negative emotions arising from the three poisons (三毒) of greed, hatred and delusion (贪嗔痴) while having less of the pure emotions. The latter, however, only have the pure emotions. Of course, they have other qualities like wisdom (智慧) and skilful means (方便) too.