How to distinguish between "X is Y" and "Y is X"?

Question

triggered by a question on how to render "The past is a thought", the naive pattern as suggested in the question is "X Y est"; In English that gives us insight on the nature of the past (X) ; it indicates what past is. But if we observe thought and recognize that the thought is the past (J. Krishnamurti) then we have insight on the nature of thought and we can render in English "thought is the past". In Latin, presumably some change in the order of the words would hint to one reading, however it would not suffice to make it unambiguous.

So what succinct pattern can we use to say "X is Y" which is also not ambiguous with "Y is X"? I was thinking perhaps relative pronoun like "X quod est Y" but I think it does not solve the problem.

Answer 1

Both sunt and est at the beginning of a sentence can means 'there are' and 'there is’ and also 'there exists'. Esse can have those meanings and others.

From M. Tullius Cicero, De Divinatione http://www.perseus.tufts.edu/hopper/text?doc=Perseus:text:2007.01.0042 Liber Secundus Section 41

Si di sunt, est divinatio; sunt autem di; est ergo divinatio. 

The following translation is also from Perseus and is by William Falconer. "If there are gods, there is divination; but there are gods, therefore there is divination. "

I didn't understood what was meant by "The past is a thought" but it could also be gramatically expressed as "There is the past which is a thought".

To differentiate X and Y with a relative clause:- There is/are X, who/which Y

est X qui/quae/quod Y (est).   

My recollection is that the second esse can be deemed redundant and dropped.

Using divinatio as X and divinus as Y, in the simple example, to place 'there is' on X such that: There is divination which is divinely inspired.

est divinatio quae divina (est)
  

In Latin using esse it can be made clear which is the subject X and which is the predicate Y.

One Classical example of sunt as 'There are' followed by a relative clause as predicate is:-

Sunt autem bestiae quaedam, in quibus inest aliquid simile virtutis, ut in leonibus, ut in canibus, ut in equis. Cic. Fin. 5. 38 M. Tullius Cicero, de Finibus Bonorum et Malorum Book 5 Section 38 Perseus http://data.perseus.org/citations/urn:cts:latinLit:phi0474.phi048.perseus-lat1:5.38

One English translation. But there are some animals which possess something resembling virtue, for example, lions, dogs and horses; https://penelope.uchicago.edu/Thayer/E/Roman/Texts/Cicero/de_Finibus/5*.html

However, though in the above examples, the inflected forms of esse are the subject, the relative clause can be made the subject instead of being the predicate.

This classical example was one of many (many not using subjunctives) using esse ( There is ; There are ; There have been) and qui (as inflected) in the book 'Rules for the construction of the Relative Qui, Quae, Quod, with the subjunctive mood, established by a copious selection of examples from Classical Authors', by A. R. Carson ( Aglionby Ross Carson ) 2nd edition. 1821 available online under Google Books. This states on p6. The nominate or subject to sunt ... if fully expressed ... is the name ... which the subsequent declaration is applied and restricted. That is, the relative clause with qui (as inflected) is the predicate. On pp13-15 and onwards the book further expresses the use of relative clauses in relation to which is subject and predicate and why, and as to how to make clear, with the use of the indicative or subjunctive forms of verbs.

Alternative expressions with clear order (not using esse) for specific attributions of meaning can also be attributed to the English 'is' when used 'to mean' were subsequently found in the book titled Greek and Latin Expressions of Meaning, The Classical Origins of a Modern Metaphor by Andreas T. Zanker . This book is available to read online at https://books.openedition.org/chbeck/1617 Expressions of Equivalance are discussed in the book Greek and Latin Expressions of Meaning Chapter 2 V. Expressions of Equivalence.

In Greek and Latin Expressions of Meaning, chapter 3: (II) Point 33 :- one means for expressing that X means (is) Y

Perseus Reference http://data.perseus.org/texts/urn:cts:latinLit:phi0474.phi049.perseus-lat1 M. Tullius Cicero, Tusculanae Disputationes Book I Section 88. A form of expression where significare can correspond with English means.

      carere igitur hoc significat: egere eo quod habere velis

Translation from Greek and Latin Expressions of Meaning:-

      This is the meaning of carere: to lack something that you wish to possess 

In Greek and Latin Expressions of Meaning, chapter 3: (II) Point 46 :- A means of expressing that while X might mean Y, Y does not mean X

LOEB Reference https://www.loebclassics.com/view/quintilian-orators_education/2002/pb_LCL127.259.xml Quintilian, Institutio Oratoria Book 10.1 Section 14

 nec ut mucro gladium, sic mucronem gladius ostendit.   
      

Translation from Greek and Latin Expressions of Meaning:-

 Although mucro denotes a sword, gladius does not denote a blade. 
 ( mucro for blade, gladius as sword ).          

The book Greek and Latin Expressions has detailed references as to when the meanings of equivalance may start to be attributed to the referred Greek and Latin verbs.

Answer 2

The rule in English seems to be that of the two things, the more specific attribute is the main subject.

"Fred" is more specific than "tall", so these mean the same unambiguously:

• Fred is tall.
• Tall is Fred.

"The dog" is more specific than "an animal", so "the dog" is unambiguously the subject:

• The dog is an animal.
• An animal is the dog.

"The animal" is more specific than "a dog", so "the animal" is unambiguously the subject:

• The animal is a dog.
• A dog is the animal.

This is true even if the articles are the same, so long as the nouns can be compared for specificity:

• A dog is an animal.
• An animal is a dog.

In each case the second instance may be awkward, but it isn't ambiguous.