Plenty of people call themselves “spiritual”. Three questions:
Question 1: What does it mean to be “spiritual”?
I don’t think there is a definitive answer to this question. From what I understand, it generally means that an individual values “higher” goals than merely physical pleasure, and is supposedly more aware of how they fit into the bigger picture. [note: I am not talking about “spiritualism”, which is a philosophy based around the existence of “spirits” which can be communicated with]
They also seem to stress reflection upon the nature of “being”, or what the “self” is. This leads to the next question:
Question 2: Does being “spiritual” require you to reject physicalism?
I know people who would describe themselves as “spiritual”, but would chafe at the idea that things exist which are non-physical. If humans are physical animals, how can there be “higher” or “lower” values? Sex releases dopamine in the brain. So does love. Where does a hierarchy of values come from if everything is reducible to physicality?
I don’t think the implications of “spirituality” are understood by those who describe themselves as spiritual. It might sound romantic to talk about the spirit of humans, but it sounds downright crazy when you flesh that belief out to its conclusions.
Question 3: Can you be spiritual without a spirit?
I think “spirituality” can be more philosophically tolerable if it doesn’t require belief in the non-physical. One that sounds something like this:
Human beings, like everything else, are entirely physical, and are not animated by a non-physical “spirit”, but by the hard-wiring inside their bodies. Some humans are hard-wired to value reproduction highest, others to value relationships, others to exercise their brain in thought; there is no objective hierarchy of values, just subjective preferences based on the specific wiring of each homo sapiens’ brain.
Of course, that kind of takes the romance out of spirituality.