sci

Latin

know, knowledge

Variants:sciscient

Your mastery

About This Root

The root sci comes from Latin scīre, "to know" — not the half-formed hunch of a guess, but real, settled knowledge: knowing how something works, knowing a fact for certain, knowing the difference between right and wrong.

The most direct descendant is science (scientia, "knowledge"). Originally it meant knowledge of any kind; only in the last few centuries did it narrow to the systematic study of the natural world. A scientist is literally a "knowledge person," and anything scientific follows the methods that build reliable knowledge.

The richest branch comes from adding con- (together, with). Con- + scīre = "to know together," to share an awareness. From this single idea English drew a whole cluster:

- conscious — knowing along with yourself; aware that you are awake, aware of what you are doing.
- consciousness — the whole state of that inner awareness.
- consciously — doing something while fully aware of it.
- conscience — the most surprising member. To the Romans, "knowing together with yourself" included knowing whether your own acts were good or bad. That inner co-witness became the moral voice we call conscience. Notice how knowledge and ethics were fused: your conscience is the part of you that knows what you did.
- conscientious — guided by that inner moral knowledge, hence careful and thorough in doing what is right.

Two more members extend the reach of knowing. omni- (all) + scient = omniscient, "all-knowing" — the property of a god or of a storyteller who sees inside every character. pre- (before) + scientia = prescience, knowing something before it happens — foresight.

The spelling shifts slightly. Before a suffix the root often appears as scient (the present-participle stem of scīre): omni-scient, pre-scient, con-scient-ious. Strip away the prefix and suffix and the same quiet claim is always underneath: I know. The family then fans out along two lines — outward toward organized knowledge of the world (science, scientific), and inward toward self-awareness and the moral sense (conscious, conscience).

From Latin scīre (to know, understand). The foundation of knowledge vocabulary: science (systematic knowledge), scientist, conscience (knowing with, moral awareness), conscious (being aware), omniscient (all-knowing). Prescience means knowing beforehand. The shift from 'knowing' to 'moral awareness' in conscience shows how knowledge and ethics were linked in Latin thought.

Memory Tip

Hear sci in science — it's all about knowing. Add con- ("with/together") and you get "knowing together with yourself": that's why conscious = aware of yourself, and conscience = the inner voice that knows whether you did right.

Core Words Deep Dive

The few words from this family worth telling in full — one by one.

science

Latin scientia simply meant 'knowledge' of any kind — moral knowledge, craft knowledge, book knowledge. For most of its history 'science' in English meant much the same thing. Only from the 1700s-1800s, as the experimental method took over, did it narrow to its modern sense: organized, testable knowledge of the natural world. The root never changed; the world's idea of what counts as real knowledge did.

conscious

con- ('together with') + sci ('know') = 'knowing together with oneself.' To be conscious is to have that inner co-knowledge: you are aware that you are awake and aware of what you are doing. The same con-+know core also produced conscience — the difference is that conscious is about awareness in general, while conscience narrowed to knowing right from wrong.

conscience

The family's most surprising leap. con- + sci literally means 'knowing with' — but to the Romans, knowing alongside yourself included knowing whether your own deeds were good or bad. That inner witness who shares your secrets became the moral voice we call conscience. This is why knowledge and ethics sit inside one word: your conscience is the part of you that knows what you really did.

omniscient

omni- ('all') + scient ('knowing') = 'all-knowing.' It describes a god who knows everything, or — in literature — a narrator who can see inside every character's mind at once. Note the spelling: before the -ent ending the root takes its participle form scient (the same stem hidden in prescient and conscientious).

Related Roots

gnostSimilar

gnost/gno comes from Greek gignōskein, 'to know,' the Greek twin of Latin scīre. It gives diagnosis (knowing through symptoms), prognosis, agnostic ('not knowing'). Quick split: Latin knowledge words tend to use sci (science, conscious); Greek ones use gno/gnost (diagnose, agnostic).

cognSimilar

cogn (Latin cognōscere = co- + gnōscere, 'to get to know') overlaps with sci but stresses the process of coming to know or recognize: recognize, cognition, incognito. sci is closer to settled knowledge or awareness (science, conscious); cogn is closer to the act of recognizing.