Martela & Steger 2016 is the best overview I’ve found of the field of meaning research. From practical empirical results, to summaries of major themes and definitions, and all the way to discussions of Tolstoy, Camus, Socrates, and Plato, it’s an amazing and dense piece of research at only 11 pages long. If anyone’s interested in this field, start with this paper. The discussion about Tolstoy made me think that his book Confession, which I read last year, is probably what sparked my search for meaning (along with Huemer’s Ethical Intuitionism which rehabilitates the concept of meaning). Be careful what you read!
An initial step in understanding psychological research on meaning in life is to separate this question from the more philosophical question about meaning of life (Debats, Drost, & Hansen, 1995). This latter question looks at life and the universe as a whole and asks what, in general, is the point of life: Why does it exist, and what purpose does it serve? These kind of metaphysical questions are, however, ‘out of reach of modern objectivist scientific methodology’ (Debats et al., 1995, p. 359), and not questions for psychology to answer. The aim of psychological research on meaning in life is more modest. It aims to look at the subjective experiences of human beings and asks what makes them experience meaningfulness in their lives. […]
Meaning, as a word, comes from the Old High German word meinen, to have in mind (Klinger, 2012, p. 24). This already reveals that meaning is tied up with the unique capacity of human mind for reflective, linguistic thinking. […] When we ask what something means, we are trying to locate that something within our web of mental representations. Meaning is about mentally connecting things. This is true whether we ask about the meaning of a thing or the meaning of our life.
Meaning is thus about life as interpreted by a being capable of reflective thinking. While the question whether animals can experience pleasure and happiness has been debated within science at least since Darwin (1872; see also McMillan, 2005), we are aware of no serious argument for animals experiencing a sense of meaning in life. Meaning, at least in its more developed forms, is thus an exclusively human affair. […]
[T]here are three basic facets of this search for meaning in life, corresponding to three different domains of human experience: coherent understanding (cognitive), worthwhile pursuing (motivational), and valuing living (evaluative). Meaning is about rising above the merely passive experiencing, to a reflective level that allows one to examine one’s life as a whole, making sense of it, infusing direction into it, and finding value in it.
The three meanings of meaning in life: Distinguishing coherence, purpose, and significance, Martela & Steger, The Journal of Positive Psychology, 2016, https://dx.doi.org/10.1080/17439760.2015.1137623