Sympathy (from the Greek words syn 'together' and pathos 'feeling' which means 'fellow-feeling') is the perception, understanding, and reaction to the distress or need of another life form. This empathic concern is driven by a switch in viewpoint, from a personal perspective to the perspective of another group or individual who is in need. David Hume explained that this is the case because 'the minds of all men are similar in their feelings and operations' and that 'the motion of one communicates itself to the rest' so that as affectations readily pass from one to another, they beget corresponding movements. Sympathy (from the Greek words syn 'together' and pathos 'feeling' which means 'fellow-feeling') is the perception, understanding, and reaction to the distress or need of another life form. This empathic concern is driven by a switch in viewpoint, from a personal perspective to the perspective of another group or individual who is in need. David Hume explained that this is the case because 'the minds of all men are similar in their feelings and operations' and that 'the motion of one communicates itself to the rest' so that as affectations readily pass from one to another, they beget corresponding movements. The words empathy and sympathy are often used interchangeably. Sympathy is a feeling, but the two terms have distinct origins and meanings. Merriam-Webster defines empathy as 'the action of understanding, being aware of, being sensitive to, and vicariously experiencing the feelings, thoughts, and experience of another of either the past or present without having the feelings, thoughts, and experience fully communicated in an objectively explicit manner'. Merriam-Webster defines that sympathy is when you share the feelings of another; empathy is when you understand the feelings of another but do not necessarily share them, as sympathy was defined by 18th century philosophers such as Adam Smith. Other social theorists cite this conceptualization in understanding another person's mind and reason, identifying it with other concepts such as 'sympathetic imitation', 'consciousness of kind', 'role-taking', 'simulation', and 'identification', among others. Grammarist.com defines sympathy as 'the feeling that you care about and are sorry about someone else's trouble, grief, misfortune, etc.'; 'a feeling of support for something'; or 'a state in which different people share the same interests, opinions, goals, etc.', but not necessarily the feeling that you share another person's emotions. In order to get an experience of sympathy there are specific conditions that need to occur. These include: attention to a subject, believing that a person/group is in a state of need, and the specific characteristics of a given situation. An individual must first give his or her attention to a person/group. Distractions severely limit the ability to produce strong affective responses. Without distractions, people are able to attend to and respond to a variety of emotional subjects and experiences. Attention facilitates the experience of sympathy, and without giving undivided attention to many situations sympathy cannot be experienced.