Everyday symbols and meanings: where common signs come from

1. Language and typography symbols

Many symbols we use in daily text messaging and email originated centuries ago as shorthand abbreviations in handwritten Latin manuscripts:

• Ampersand (&): The ampersand began as a cursive ligature of the letters e and t (spelling et, Latin for “and”). Roman scribes joined the letters to save parchment, creating the flowing shape we recognize today.
• At sign (@): Long before the internet, medieval Venetian merchants used @ as an abbreviation for anfora (amphora), a standard jar unit of measure. In nineteenth-century commerce, it became “commercial at” (e.g., “5 apples @ $1 each”). Ray Tomlinson chose it in 1971 for email addresses because it indicated a user's location without appearing in any human surname.
• Pilcrow (¶): The paragraph symbol evolved from the Latin letter C for capitulum (little head or chapter). Monks illuminated the letter with colored ink to indicate the start of a new argument before the invention of line indents.

2. Mathematical and logic symbols

Mathematical notation underwent rapid standardization during the European scientific revolution:

• Infinity (∞): English mathematician John Wallis introduced the lemniscate curve (∞) in 1655 in his treatise on conic sections. While Wallis never explained why he chose it, historians link it to the Roman numeral for 1,000 (ↀ) or the Greek letter omega (ω). Explore its deeper philosophical associations on our infinity symbol page.
• Therefore (∴) and Because (∵): Swiss mathematician Johann Rahn introduced ∴ in 1659 to conclude logical syllogisms. The inverted triangle of dots (∵) emerged later to introduce deductive premises.
• Pi (π): Welsh mathematician William Jones first used the Greek letter π in 1706 to represent the ratio of a circle's circumference to its diameter, shorthand for the Greek word perimetros (perimeter). Leonhard Euler popularized the notation worldwide in 1737.

3. Commerce and currency signs

Currency signs carry centuries of political and monetary history:

• Dollar sign ($): The dollar sign developed from the handwritten abbreviation for Spanish American silver pesos (“pieces of eight”), which were legal tender in early America. Merchants wrote “Ps” with the S superimposed over the P, eventually simplifying into an S with one or two vertical bars.
• Pound sign (£): The pound sign is a stylized capital letter L crossed with a horizontal bar, standing for libra, the ancient Roman unit of weight that formed the basis for the British pound sterling.
• Euro sign (€): The European Commission designed the euro sign in 1996. Inspired by the Greek letter epsilon (ϵ), it references the cradle of European civilization and the initial letter of “Europe”, while the two horizontal parallel lines symbolize monetary stability.

4. Social, philosophical, and cultural emblems

Human societies create powerful visual emblems to rally movements and express core values:

• Peace sign (☮): British artist Gerald Holtom designed the peace sign in 1958 for the Campaign for Nuclear Disarmament. He combined the naval flag semaphore signals for the letters N (Nuclear) and D (Disarmament) inside a circle representing the earth. Read more on the peace sign page.
• Heart symbol (♥): The iconic heart shape bears little resemblance to human anatomy. Historians trace it to depictions of the extinct North African silphium plant seed, whose heart-shaped pods were prized as herbal spices and birth control in antiquity, before spreading through courtly romance art in medieval Europe.
• Yin Yang (☯): Originating in ancient Chinese Daoism, the taijitu represents dynamic balance between complementary opposing forces (light and dark, active and receptive). Explore its philosophical context in our guide on the symbol for balance.

5. Safety, science, and medicine signs

Modern warning symbols are engineered with rigorous psychological research:

• Biohazard (☣): Unlike ancient symbols, the biohazard sign was scientifically designed in 1966 by Charles Baldwin at Dow Chemical. Researchers tested dozens of geometric configurations to create a mark that was memorable, striking, and completely devoid of prior cultural associations so it would be recognized across all languages.
• Radiation trefoil (☢): Invented at the University of California, Berkeley Radiation Laboratory in 1946, the three-bladed trefoil represents activity radiating outward from an atom.
• Staff of Aesculapius (⚕) vs Caduceus (☤): The true historical symbol of medicine is the Staff of Aesculapius—a single snake wrapped around a rough wooden walking stick, representing healing and rebirth through the shedding of snake skin. In North America, commercial organizations frequently confuse it with the Caduceus (a winged staff with two entwined snakes), which was the wand of Hermes, the Greek god of commerce and thieves!

For more symbolic journeys, explore our thematic collections like symbols for love, symbols for death, and symbols for life.