Eros ( /ˈɪrɒs/ or /ˈɛrɒs/; Ancient Greek: ἔρως érōs) is one of the four words in Ancient Greek which can be rendered into English as “love”. The other three are storge, philia and agape. Eros refers to “intimate love” or romantic love; storge to familial love; philia applies to close friends; and agape refers to “selfless love”, or “charity” as it is translated in the Christian scriptures (from the Latin caritas, dearness). The term erotic is derived from eros. Eros has also been used in philosophy and psychology in a wider sense, almost as an equivalent to "life energy".

In Ancient Greek, eros means "intimate love". The Modern Greek word is erotas.

In the classical world, erotic love was generally referred to as a kind of madness or theia mania ("madness from the gods"). This love passion was described through an elaborate metaphoric and mythological schema involving "love's arrows" or "love darts", the source of which was often the personified figure of Eros (or his Latin counterpart, Cupid), or another deity (such as Rumor). At times the source of the arrows was said to be the image of the beautiful love object itself. If these arrows were to arrive at the lover's eyes, they would then travel to and 'pierce' or 'wound' his or her heart and overwhelm him/her with desire and longing (love sickness). The image of the "arrow's wound" was sometimes used to create oxymorons and rhetorical antithesis concerning its pleasure and pain.

Eros (/ˈɪərɒs/, US: /ˈɛrɒs/; Ancient Greek: Ἔρως, "Desire"), in Greek mythology, was the Greek god of love. His Roman counterpart was Cupid ("desire"). Some myths make him a primordial god, while in other myths, he is the son of Aphrodite.

The Shaftesbury Memorial in Piccadilly Circus, London, is popularly mistaken for Eros. In fact it represents Anteros.

Eros appears in ancient Greek sources under several different guises. In the earliest sources (the cosmogonies, the earliest philosophers, and the mysteries), he is one of the primordial gods involved in the coming into being of the cosmos. But in later sources, Eros is represented as the son of Aphrodite whose mischievous interventions in the affairs of gods and mortals cause bonds of love to form, often illicitly. Ultimately, in the later satirical poets, he is represented as a blindfolded child, the precursor to the chubby Renaissance cupid – whereas in early Greek poetry and art, Eros was depicted as an adult male who embodies sexual power.

The word concept is defined variously by different sources. Philosophers and others generally agree that concepts are formed from experience and other pre-existing mental content by abstraction and other operations in the brain.

John Locke's description of a general idea corresponds to a description of a concept. According to Locke, a general idea is created by abstracting, drawing away, or removing the uncommon characteristic or characteristics from several particular ideas. The remaining common characteristic is that which is similar to all of the different individuals. For example, the abstract general idea or concept that is designated by the word "red" is that characteristic which is common to apples, cherries, and blood. The abstract general idea or concept that is signified by the word "dog" is the collection of those characteristics which are common to Airedales, Collies, and Chihuahuas.^{[citation needed]}

John Stuart Mill argued that general conceptions are formed through abstraction. A general conception is the common element among the many images of members of a class. "...[W]hen we form a set of phenomena into a class, that is, when we compare them with one another to ascertain in what they agree, some general conception is implied in this mental operation" (A System of Logic, Book IV, Ch. II). Mill did not believe that concepts exist in the mind before the act of abstraction. "It is not a law of our intellect, that, in comparing things with each other and taking note of their agreement, we merely recognize as realized in the outward world something that we already had in our minds. The conception originally found its way to us as the result of such a comparison. It was obtained (in metaphysical phrase) by abstraction from individual things" (Ibid.).