Sage (philosophy) in the context of "Three Sovereigns and Five Emperors"

An expert is somebody who has a broad and deep understanding and competence in terms of knowledge, skill and experience through practice and education in a particular field or area of study. Informally, an expert is someone widely recognized as a reliable source of technique or skill whose faculty for judging or deciding rightly, justly, or wisely is accorded authority and status by peers or the public in a specific well-distinguished domain. An expert, more generally, is a person with extensive knowledge or ability based on research, experience, or occupation and in a particular area of study. Experts are called in for advice on their respective subject, but they do not always agree on the particulars of a field of study. An expert can be believed, by virtue of credentials, training, education, profession, publication or experience, to have special knowledge of a subject beyond that of the average person, sufficient that others may officially (and legally) rely upon the individual's opinion on that topic. Historically, an expert was referred to as a sage. The individual was usually a profound thinker distinguished for wisdom and sound judgment.

In specific fields, the definition of expert is well established by consensus and therefore it is not always necessary for individuals to have a professional or academic qualification for them to be accepted as an expert. In this respect, a shepherd with fifty years of experience tending flocks would be widely recognized as having complete expertise in the use and training of sheep dogs and the care of sheep.

Wisdom literature is a genre of literature common in the ancient Near East. It consists of statements by sages and the wise that offer teachings about divinity and virtue. Although this genre uses techniques of traditional oral storytelling, it was disseminated in written form.

The earliest known wisdom literature dates back to the middle of the 3rd millennium BC, originating from ancient Mesopotamia and Egypt. These regions continued to produce wisdom literature over the subsequent two and a half millennia. Wisdom literature from Greek, Chinese, and Indian cultures started appearing around the middle of the 1st millennium BC. In the 1st millennium AD, Egyptian-Greek wisdom literature emerged, some elements of which were later incorporated into Islamic thought.

Tannaim (Amoraic Hebrew: תנאים [tannɔʔim] "repeaters", "teachers", singular tanna תנא [tanˈnɔː], borrowed from Aramaic) were the rabbinic sages whose views are recorded in the Mishnah, from approximately 10–220 CE. The period of the Tannaim, also referred to as the Mishnaic period, lasted about 210 years. It came after the period of the Zugot "Pairs" and was immediately followed by the period of the Amoraim "Interpreters".

The root tannā (תנא) is the Aramaic equivalent of the Hebrew root shānā (שנה), which also is the Semitic root found in the word Mishnah. Shana means "to repeat [what one was taught]" and is used to mean "to learn".

Ben Sira, also called Ben Sirach, Jesus ben Sira, Joshua ben Sira, or Sirach (Hebrew: שמעון בן יהושע בן אליעזר בן סירא, romanized: šimʿon ben yəhošuʿ ben ʾəliʿezer ben Sirā; fl. 2nd century BCE) was a Hellenistic Jewish scribe, sage, and allegorist from Seleucid-controlled Jerusalem of the Second Temple period. He is the author of the Book of Sirach, also known as "Ecclesiasticus".

Ben Sira wrote his work in Hebrew, possibly in Alexandria in the Ptolemaic Kingdom c. 180–175 BCE, where he is thought to have established a school.

Apollonius of Tyana (Ancient Greek: Ἀπολλώνιος ὁ Τυανεύς; c. AD 15 – c. 100) was a Greek philosopher and religious leader from the town of Tyana, Cappadocia in Roman Anatolia, who spent his life travelling and teaching in the Middle East, North Africa and India. He is a central figure in Neopythagoreanism and was one of the most famous "miracle workers" of his day.

His exceptional personality and his mystical way of life, which was regarded as exemplary, impressed his contemporaries and had a lasting cultural influence. Numerous legends surrounding him and accounts of his life are contained in the extensive Life of Apollonius. Many of the ancient legends of Apollonius consist of numerous reports about miracles that he was said to have performed as a wandering sage with his lifelong companion Damis.

Aniconism is the cultural absence of artistic representations (icons) of the natural and supernatural worlds, or it is the absence of representations of certain figures in religions. The prohibition of material representations may only extend to a specific supreme deity, or it can encompass an entire pantheon, it can also include depictions of a prophet, saints, or sages, or even depictions of living beings and anything in existence generally. It is generally codified by religious traditions and as such, it becomes a taboo. When it is enforced by the physical destruction of images, aniconism becomes iconoclasm.

Aniconism has historical phases in both Buddhism and Christianity, though these movements have been largely rejected as Buddha in art, life of Buddha in art, Buddhas and bodhisattvas in art, God the Father in Western art, Holy Spirit in Christian art, the depiction of Jesus, The Trinity in art, and Manus Dei are common. By contrast Islam has predominantly been aniconistic throughout their histories, including representations of major figures such as Muhammad. The view of aniconism in Judaism has been challenged, with a number of medieval Ashkenazi illuminated manuscripts collected by David Kaufmann. The earliest phases of ancient Greek religion were rich in aniconic representation, even though Greek mythology is heavily anthropomorphic.

In Hellenistic philosophy, phantasiai (φαντασίαι) are pieces of information received from sense experience. The Pyrrhonists, Epicureans, and Stoics use the term to refer to information received through the senses and arising in thoughts.

In Stoicism, the phantasiai represent pre-cognitive judgments originating from our previous experiences or our subconscious thinking. The founder of Stoicism, Zeno of Citium, suggested that the soul is imprinted by the senses much in the same way as a signet ring imprints its shape in soft wax; all psychological states and activities, such as mental assent, cognition, impulse, and knowledge are all either extensions or responses to phantasiai. According to Epictetus, the sage avoids doxa, a weak or false belief, by withholding assent when conditions do not permit a clear and certain grasp of the truth of a matter. Some phantasiai experienced in perceptually ideal circumstances, however, are so clear and distinct that they could only come from a real object; these were said to be kataleptikê (fit to grasp). The kataleptic phantasiai compels assent by its very clarity and represents the criterion of truth.