Difference between ideogram and logogram?

Question

I'm having a bit of trouble differentiating these, and I'm wondering if it's because these are generally fuzzy concepts and nobody cares much, if I haven't read into it enough, if my innate assumptions about spoken language are obfuscating the definitions, etc.

Consider this: The   ⃠   (No, not allowed, banned, etc) symbol is considered a pictogram, which by the format of the answer to the linked question, is a subset of the ideograms. However, it is usually seen composed with other pictograms (such as   ⃠    💩  superimposed), or coupled with another ideogram. If written Chinese is often taken as logographic, not ideographic, since logograms are defined as representing morphemes, basic units of meaning, rather perhaps more nebulous notions represented by ideograms (which I suppose all the major religous symbols would fit, e.g. dharmacakra☸, arguably ichthys, orthodox cross☦, peace symbol ☮, etc), then would the composition of this pictogram with a Chinese logogram now be a pictogram or a logogram? I find it tough to decide since it doesn't necessarily have a word in that language which represents it, since some words or emerging ideologies don't have clear antithetical terms, but sometimes they do? While nuclear weapons are arguably not an ideology, would the classic "no nuclear weapons symbol" fit into any category neatly?

Finally, i'm not really sure if a difference based on "idea, concept" vs "word, morpheme" vs "symbol representing concept which bares resemblence to physical manifestation" is that sensible, since aren't words pretty much abstract, conceptual "placeholder" symbols. I'm not well read on linguistics at all, so I don't know if Ludwig Wittgenstein is discredited, but he felt humans communicated by mapping "mental images" to words.

Inspiration: From Relation between some linguistics terms we have:

logogram or logograph - represents a morpheme or word, e.g. the Mandarin copula ⟨是⟩; ⟨&⟩ 'and', ⟨@⟩ 'at', ⟨$⟩ 'dollar' in English

ideogram or ideograph - represents an concept, e.g. ⟨上⟩ 'up' in Chinese/Japanese; digits like ⟨8⟩ 'eight'; ⟨♡⟩ 'love'; the no symbol ⟨  ⃠  ⟩; the red octagonal stop sign

pictogram or pictograph - an ideogram consisting of a pictorial representation of its referent, e.g. ⟨木⟩ 'tree' in Chinese/Japanese, ⟨💩⟩ 'pile of poo', many emoticons, astronomical symbols like ⟨☽⟩ 'waxing crescent moon'

Answer 1

This is a collection of mostly German references I found:

1. Doblhofer, Ernst: Die Entzifferung alter Schriften und Sprachen (The deciphering of ancient scriptures and languages), Wien, 1957: He makes a difference between a "Wortbildzeichen" (word picture sign) which he calls ideogram and a "Wordlautzeichen" (word sound(?) sign) which is a logogram to him. A word picture sign is something like a pictogram. The picture of a house may stand for "Haus", "house", "maison", "casa", maybe for "cottage", "palace" as well. A word sound sign has a codified reading: it can only be read "house".

2. Falkenstein, A: Das Sumerische (The Sumerian), Leiden, 1964: He does only speak of "Wortzeichen" (word signs) which are mostly polyphonic. I think this is the meaning of Doblhofer's "word picture sign".

3. Ungnad, Matous: Grammatik des Akkadischen (Akkadian Grammar): München, 1969: seems to use "Wortzeichen" (word signs), logogram, and ideogram with no distiction between them (§3a).

4. Borger, Rylke: Assyrisch-babylonische Zeichenliste (Assyrian Babylonian cuneiform list), Neukirchen-Vluyn, 1988: Borger does not distinguish between the terms. He subsumes logogram, ideogram, and sumerogram under "Wortzeichen" (§3E) and says that logogram is the most common one at the time of writing.

5. von Soden, Wolfram: Grundriss der akkadischen Grammatik (Outline of the Akkadian Grammar), Rom, 1995: He speaks of "Wortzeichen" (word signs) and discourages the term ideogram (§5c). Word signs might be polyphonic.

This list is by no means concluding. I would appriciate of other users would add more references. However, from this list it seems that the difference between ideogram and logogram is a bit artificial and not consistent accross the literature. Especially for languages written in cuneiforms we may not be able to make the distinction, because the signs have a syllabic (phonetic) reading too, as well as the reading of the signs changed over the time.