Soap has been around for thousands of years, dating back to the Romans, Egyptians, and Babylonians.
The earliest soaps had just one ingredient: oil or fat, which lathered and washed dirt away when an alkali was added to saponify it.
In the 1800's, soap went from a homey product created for personal use to industrial mass production. Fats for soap making were hard to source during World War I, though, even for industry giants. So out of necessity, industrial chemists created detergent cleansers -- synthetic surfectants masquerading as "soap," made from artificial compounds, preservatives, fragrances, and dyes.
When it became clear that detergents cost far less to manufacture than soaps, they were heavily marketed to consumers -- even after the war ended, and fats for soap making became available again.
What followed was decades of detergent cleansing bars advertised as "better than" real soap because they were more fragranced, and didn’t leave a film. More recently, antibacterial qualities were added, and their super-cleaning properties were aggressively marketed as "better," too.
Cheap as they may be to manufacture, detergents have a dark side. Synthetic cleansers can be harsh and drying, stripping skin of the naturally protective moisture barrier that keeps skin intact and bad germs out. Their artificial ingredients can irritate skin and mucus membranes; some are carcinogenic. While antibacterial agents are desirable in theory, in practice they kill more helpful bacteria than harmful ones. And lab-created surfectants, washed down drains and into our water supply, can damage creatures and their ecosystems across the long span of time required for them to break down.
The good news is this: pure, real soap, simply made, still exists -- and it works beautifully and healthfully to cleanse body and spirit, just as it has for thousands of years. Scented with natural plant essences (or not scented at all,) true soap is truly better for you, and for our environment.
Traditional Aleppo soap from Syria.
Image by yeowatzup from Katlenburg-Lindau, Germany, (Souq al-Bzouriyya, Damascus, Syria), [CC BY 2.0 (via Wikimedia Commons