The concept of mind ( /ˈmaɪnd/) is understood in many different ways by many different traditions, ranging from panpsychism and animism to traditional and organized religious views, as well as secular and materialist philosophies. Most agree that minds are constituted by conscious experience and intelligent thought. Common attributes of mind include perception, reason, imagination, memory, emotion, attention, and a capacity for communication. A rich set of unconscious processes are also included in many modern characterizations of mind.
Theories of mind and its function are numerous. Earliest recorded speculations are from the likes of Zoroaster, the Buddha, Plato, Aristotle, and other ancient Greek, Indian and, later, Islamic and medieval European philosophers. Pre-modern understandings of the mind, such as the neoplatonic "nous" saw it as an aspect of the soul, in the sense of being both divine and immortal, linking human thinking with the un-changing ordering principle of the cosmos itself.
Which attributes make up the mind is much debated. Some psychologists argue that only the "higher" intellectual functions constitute mind, particularly reason and memory. In this view the emotions—love, hate, fear, joy—are more primitive or subjective in nature and should be seen as different from the mind as such. Others argue that various rational and emotional states cannot be so separated, that they are of the same nature and origin, and should therefore be considered all part of what we call the mind.
In popular usage mind is frequently synonymous with thought: the private conversation with ourselves that we carry on "inside our heads." Thus we "make up our minds," "change our minds" or are "of two minds" about something. One of the key attributes of the mind in this sense is that it is a private sphere to which no one but the owner has access. No one else can "know our mind." They can only interpret what we consciously or unconsciously communicate.