The self is an individual person as the object of his or her own reflective consciousness. The self has been studied extensively by philosophers and psychologists and is central to many world religions.

The philosophy of self seeks to describe essential qualities that constitute a person's uniqueness or essential being. There have been various approaches to defining these qualities. The self can be considered that being which is the source of consciousness; the agent responsible for an individual's thoughts and actions; and/or the substantial nature of a person which endures and unifies consciousness over time.

The philosophy of a disordered self, such as in schizophrenia, is described in terms of what the psychiatrist understands are actual events in terms of neuron excitation but are delusions nonetheless, and the schizo-affective or schizophrenic person also believes are actual events in terms of essential being. PET scans have shown that auditory stimulation relates to certain areas of the brain and imagined similar events occur in adjacent areas but hallucinations occur in the same areas. In such cases, external influences may be the source of consciousness and the person may or may not be responsible for "sharing" in the mind's process; and/or the events which occur, such as visions and auditory stimuli, may endure and be repeated often over hours, days, months or years -- and the afflicted person may believe themselves to be in a state of rapture and/or possession, which their artistic expression may tend to confirm. Whether art has moral responsibility is difficult to relate to the idea of a unique source of consciousness and rapid thinking may lead to an insubstantial nature of the enduring person's consciousness over time; it can be said in view of these two exigencies that the person is vulnerable.

Data ( /ˈdeɪtə/ DAY-tə, /ˈdætə/ DA-tə, or /ˈdɑːtə/ DAH-tə) are values of qualitative or quantitative variables, belonging to a set of items. Data in computing (or data processing) are often represented by a combination of items organized in rows and multiple variables organized in columns. Data are typically the results of measurements and can be visualised using graphs or images. Data as an abstract concept can be viewed as the lowest level of abstraction from which information and then knowledge are derived. Raw data, i.e., unprocessed data, refers to a collection of numbers, characters and is a relative term; data processing commonly occurs by stages, and the "processed data" from one stage may be considered the "raw data" of the next. Field data refers to raw data collected in an uncontrolled in situ environment. Experimental data refers to data generated within the context of a scientific investigation by observation and recording.

The word data is the plural of datum, neuter past participle of the Latin dare, "to give", hence "something given". In discussions of problems in geometry, mathematics, engineering, and so on, the terms givens and data are used interchangeably. Such usage is the origin of data as a concept in computer science or data processing: data are numbers, words, images, etc., accepted as they stand.