'elements', are the ultimate constituents of a whole.
(1) The 4 physical elements (dha^tu or maha^-bhúta), popularly called earth, water, fire and wind, are to be understood as the primary qualities of matter. They are named in Pa^li: pathavi^-dha^tu, a^po-dha^tu, tejo-dha^tu, and va^yo-dha^tu. In Vis.M. XI, 2 the four elements are defined thus: "Whatever is characterized by hardness (thaddha-lakkkhana) is the earth or solid-element; by cohesion (a^bandhana) or fluidity, the water-element; by heating (paripa^cana), the fire or heat-element; by strengthening or supporting (vitthambhana), the wind or motion-element. All four are present in every material object, though in varying degrees of strength. If, for instance, the earth element predominates, the material object is called 'solid', etc. - For the analysis of the 4 elements, s. dha^tu-vavattha^na.
(II) The 18 physical and mental elements that constitute the conditions or foundations of the process of perception, are:
1. visual organ (eye) 9. gustative object
2. auditory organ (ear) 10. body-impression
3. olfactory organ (nose) 11. eye-consciousness
4. gustatory organ (tongue) 12. ear-consciousness
5. tactile organ (body) 13. nose-consciousness
6. visible object 14. tongue-consciousness
7. sound or audible object 15. body-consciousness
8. odour or olfactive object
16. mind-element 17. mind-object
1-10 are physical; 11-16 and 18 are mental; 17 may be either physical or mental. - 16 performs the function of advertence (a^vajjana) towards the object at the inception of a process of sensuous consciousness; it further performs the function of receiving (sampaticchana) the sensuous object. 18 performs, e.g., the function of investigation (santi^rana), determining (votthapana) and registering (tada^rammana) - (for its other functions, s. Table I). For the 14 functions of consciousness, s. vin~n~a^na-kicca.
Cf. M. 115; S. XIV and especially Vibh. II (Guide p. 28f), Vis.M. XV, 17ff.
Of the many further groupings of elements (enumerated in M. 115), the best known is that of the 3 world-elements: the sensuous world (ka^ma-dha^tu), the fine-material world (rúpa-dha^tu), the immaterial world (arúpa-dha^tu); further the sixfold group: the solid, liquid, heat, motion, space, consciousness (pathavi^, a^po, tejo, va^yo, a^ka^sa, vin~n~a^na; s. above I), described in M. 140; see also M. 112.