So, what is "spirituality"? In a research paper entitled, "Spirituality as an Essential Determinant for the Good Life, its Importance Relative to Self-Determinant Psychological Needs," Dr. Dirk van Dierendonck, associate professor of organizational behavior at the Rotterdam School of Management, defines spirituality in this way,
Spirituality is usually associated with living by your inner truth to produce positive attitudes and relationships in your life (Hawley 1993). Deﬁnitions of spirituality deal with the ultimate goal in life, the experience of a transcendent dimension that gives meaning to existence, and the capacity to experience the sacred (Giacalone and Jurkiewicz 2003). Spirituality is associated with a focus on the essence of life, creativeness, spirit, mystical experiences, and new age beliefs (Zinnbauer et al. 1997; Mitroff and Denton 1999). Spirituality signiﬁes the inner attitude of living life directly related to the sacred. This deﬁnition is directly related to what Pargament (2002, p. 169) calls the essence of spirituality, that is ‘‘the process through which people discover, conserve and rediscover the sacred.’’688 D. van DierendonckSpirituality, that is, is a way of living, an experience, and a process. Those are three very different things and when taken together are very broad and inclusive of virtually all of life. Drinking (as in alcohol) can be a way of living, an experience, and a process, but we don't usually associate it with spirituality—quite the opposite. Engaging in a profession or being an enthusiastic supporter of a sports team involve ways of living, experiences, and processes. So the question is, spirituality is a way of living, an experience, and a process involving what?
Van Dierendonck's list of "whats" is long and just about as broad. Spirituality involves inner truth, positive attitudes, relationships, ultimate goals, the transcendent, meaning, the sacred, the essence of life, creativeness, spirit, mystical experiences, and new age beliefs. On reflection, that is about as clear as mud. What precisely does "inner truth" mean? Are there inner and outer truths? What distinguishes them? Or, again, what are "ultimate goals"? How do they differ from other kinds of goals? What makes them ultimate? What, indeed, do we mean here by "ultimate"? The "essence of life" is particularly nebulous. Does life have an "essence"? What might it be? The concept of "spirit" is complex and involves another set of questions. What spirituality is about, thus, is unclear, profoundly so.
The upshot of it all is that those who intend to study spirituality empirically face a daunting task beginning with all of the difficulties involved in simply defining the concept of spirituality in a way that is both inclusive of human spiritual experience and precise enough to actually describe something that is not simply another name for "the good life." Just deciding the relationship of spirituality to the religious concept of "the sacred" is going to be difficult and involve deciding whether or not spirituality has to do with the divine or not. Is there a non-theistic or secular spirituality? If so, what is it and what links it to concepts of "the spirit"?
Studying spirituality is not like studying religion or belief systems or ritual practices. Religions are institutions. Belief systems are forms of ideology. Ritual practices involve human behavior. These things can be defined concretely and studied empirically. Spirituality is something different, and my point for this posting is that van Dierendonck's attempts to define it leave him with nothing that can actually be defined with the precision a scientific approach requires.