In the transcriptions of Greek to follow, the rough breathing is written as an apostrophe, but would be "h" in English.  It was not pronounced in the Hellenistic period.  "Y" is written not only for the vowel ypsilon but also for the consonant gamma when it precedes an e or i sound in Hellenistic Greek.  (Where the font is available, the y should have a bar crossing it's lower tail.)   Note that (at first in Palestine and Alexandria rather than Athens) the sound "e" was written "ai" as well as with epsilon.  The sound "i" (was represented not only by iota but also by ypsilon, eta, and the three diphthongs (other than ai) ending in "i":  ei, oi, yi.

     Some of the items are repeated in different contexts with differ- ent contrasts.  Of course, the meaning of any term may (often) over- lap the way their English glosses (translations) overlap.

      NOÛS--transcendent or intuitive insight and perception of myste- ries beyond and higher than reason; it is not a faculty but an energy— the normal mode of reasoning among the Angelic Beings but among humans used to approach God through Grace and eventually to behold the uncreated Light.

dýnameis "powers, 
faculties, capacties"—or the 
results of energizations

energizations

lógos "(theoretical) reason, 
   rational principle" and the adjective logastikón "rational, reason-using"; logikón is "rational, reasonable"; lógimon is "noteworthy"

sýnesis "discerning, insight,    comprehending" 

See dianóēsis below for "reasoning" 

phrén (with eta), "mind" (cf. noûs)
phrónēma "mentality"; "mindset, 
    attitude, outlook, thought, 
    purpose"; contrast with 
aísthēma "experiential knowledge"

phrónēsis "thinking [in general]"

nóēma "concept"—contrast with 
aísthēma "experiential knowledge"

dián(o)ia "discursive reason,"
(dia)nóēma "thought, concept"

dianóēsis  "reasoning"

sophía "wisdom, prudence"
   (practical   reason)

[sophismόs does not fit here; it’s like  sóphisma “quibble, ingenious argument/device”]

evmátheia "aptitude  for 
   learning, talent"
gnómē(with omega)theia "opinion, viewpoint,  
   acumen, freechoice" (v. infra)

sýnnoia "deliberation"
énnoia "conceptualization"
epínoia "notion" (epinoía [dat.  
     sg.] can mean "notionally")
syllogismós "ratiocination"
máthēsis "knowing"

    While feminine nouns ending in -ia are ambiguous, those ending in -sis (-tis after -s-) are verbal nouns representing an energization (rather like English gerunds except that they lack tense and diathesis); they are often paired with a corresponding neuter ending in -ma that indicates the result of the paired energization.  These nouns have the accent as far from the end as the accent can be.  Masculines ending in -ismôs are similar to English forms ending in -(ifica)tion and -ization; English -ism in mechanism is like the Greek, but the formative often refers to an ideology or such- like.    While enérgesis is not found and harmartēsis is rare, an enérgēma is something energized and hamártēma is a "sin"—contrasting with hamartía "a sin-conducive state" brought about by humanity's separation from divine Grace (cháris, uncreated Energy, the Life of God) at the Fall.  Words for a faculty or power (and sometimes even the result of its being energized) often end in -ia; cf. enérgeia, sophía, and the regressively accented forms in -noia—but cf. lógos, phrén, and gnóme (whose vowels are omega and eta).  Logeía is a "collection" (of taxes or the like); logismós is "reckoning, reasoning" (see further below); in the plural in Patristic Greek:  logismoí "disturbing thoughts"; lógisma is a "computation" or an "argument" (for or against something); logistés is a teacher of arithmetic or an auditor; logistévein is "administer."  The adjective logikón has various senses having to do with prose eloquence or with reasoning and arguing.  Sometimes a base has added forms in, say, both -e-sis/-e-ma and -ef-sis/-ev-ma based on the verb ending in -é like logévein "collect" (taxes or the like).   The verb corresponding to pístis "believing, trusting, assuring" is pistévein "believe, trust"; hence pístefsis "confiding in" and the rare pístevma "warranty."  Many words ending in -eia  etymologically end in -ewia (with "i" accented or not) and older *-ewya-- from which the "w" disappeared in pre-Classical Greek.  This explains the correspondence of some such nouns with verbs having -ev- (from *ew) before the inflections; this -ev- changes to -ef- before p(h), t(h), k(h) and s—as in -efsis.  See below for more on many of these and other terms, of which Greek has an abundance.  The old *w turns up in noûs but drops out in noētikón "noëtic."

     The traditional make-up of a human being has included spirit as well as mind, will, emotions.  (Our hankerings, cravings, yearnings, or urges are referred to as the "passions" in not very idiomatic translations of the ancient languages.  A human has a body and a spirit or soul—pnévma.  In Luke 23:46, Christ committed his pnévma to God.   The term psyché, sometimes rendered as "soul," basically refers to "[animal] life."  Spiritual, everlasting "life" (living on the uncreated Energies of Grace) is zoé.

     In Chh. 17-21 of Book II of the Exact Exposition of the Orthodox Faith, St. John of Damaskos analyses various mental functions and emotions.  Ch. 22 defines energy in relation to them.  St. John  distinguishes two energies of the psyché—the cognitive and the vital (life-giving).   Two energetic verbal nouns for "will" are diffentiated—feminines ending  in -sis [from -tis], thélesis, voúlesis— and implicitly and explicitly, the corresponding static words (neuters ending -ma)—thélema “faculty or power of will” and voúlema “purpose, intent.”  The latter comes close to proaíresis "preference."  Cf. below for epiloyé "choice."  Note also that gnóme is both "intention" and "free choice" as well as "insight, intelligence, opinion, disposition, acumen," and "good sense."  (Will is a part of cognition for the Greeks, whereas Protesantantism makes will independent of and higher than reason.)   Both thélesis ("rational willing, deliberation") and voúlesis are energies; and energy is “drastic”—St. John defines drastic as self-initiated or self-impelled—movement.  These are distinguished from the willer or one who wills (thélon).  Voúlesis is a subcategory of thélesis or willing that has as it object a specifically (doable or not doable) intended thing, while thélesis is the more general expression.  St. John calls thélesis a “simple dýnamis”; but we will see in Ch. 23 that the relation of enéryeia (energy, i.e. “actualization,  realization,”; “action, activity”; "function"; or “effect, result”) to dýnamis “power” ("force" or" potential[iality]"), even a “faculty” of the mind.)   Crucial use is made of the term órexis  in conceptualizing both terms for will.  See below. 
     St. John notes here that while energy is basically “drastic,” it is also used in contrast with emotions (passions)—the latter being movements at variance with nature, while energy is in conformity with natureppit is natural.  Energy is life and the source of kínesis “movement”—indeed, a self-impelled movement "according to noûs" (which is a human's most elevated, intuitively apprehending mental faculty)—and aísthesis “feeling, the emotions.”
     Ch. 22 of Book II insists that dýnamis is one thing; energy, another.  not to have an energy is not to exist.  (See more on nature in III.11.  Incidentally, the Latin translation of energies in the Migne edition is actus aut operationes “acts or operations.”  But activity per se is not the CAUSAL activity of energy.  Cf. vera naturae operatio seu actus est vita “the true operation of nature or act[ualization] is life.”  The Latin heading for one section in this chapter  is Vita prima naturae operatio “life, the first operation [or function] of nature.”)  
      Energy is the primal, perpetually moving natural force or activity innate in each intelligence soul; as just observed, energy defines and manifests an essence, so that to have the same essence is to have the same energy—and mutatis mutandis.   Energy is thus the logos or rationale (raison d'être) of an essence, spring out of that essence  Energy contrasts correspondingly with both a dýnamis—a latent force or power of (and of course in accord with) a nature, which gets actualized or realized by energy—and with páthos—a condition of being affected by an energy.    (For the energetic character of mental activity and the emotions, CLICK HERE.  St. John defines nature as including knowing and life—and life is of course a prime example of energy.  He doesn't mention rational will, having just dealt with it in the foregoing chapter, but he means for it to be  included among "all of the faculties that we have already discussed.")    
     While a given energy is in accord with a given essence as is thus "natural," a nature can be acted on by an external energy that is at variance with the nature (and its energies—life, etc.) acted on.  This is  páthos.  If the actions or operations resulting from energy are also called energies (e.g. eating or drinking), St. John notes that a páthos "of nature" (e.g.  hunger and thirst) can also be an energy—presumably because it is the lack of something that promotes a nature.  This way of speaking is surprising but can be reconciled (in the manner just presumed) with the concept of a páthos is both non-energetic and contrary to nature.  Even energy can in some sense be, we read, a  dýnamis.   If the “primary” sense of energy is that it “alone is the true and voluntary, indeed rational (loyiké) and independent, life—characterizing our race,” there is another sense which takes account of the pair-like character of dýnamis and energy; for St. John can call energy the “primary perpetual dýnamis of the noëtic psyché," noting that there is a secondary sense of energy in which potential and actual are intimately linked—as when a child is a potential, but not yet actual, scholar.  Compare the way a lack like hunger or thirst can be "energizing":  The scholar is lacking in the child but is not absent from its potential.  One can thus think of an energy as "empowering":  The idea seems to be that  when a dýnamis or potential lacks actualization, that very lack impels an essence to realize itself—"its full potential."  Grace is then an Energy that "assimilates" the Icon of God (reason and freewill) to the actualized Divinization of the Icon's potential.
       The Latins, following the Cordovan Aristotelians, took essence to be energy—actus purus in the case of divine Essence—; the Reformers specified that the energy in question is will, whereas for the Latins, it is existence—and is more rational than volitional.  But energy always remained a function of essence in the East, separate from essence but identical with the divine Being.  (Some Western thinkers separated nature form essence, the former being a function of the latter.)  As essence and energy (actus) are not distinct in the West, there is no real distinction between théosis “energetic Divinization” and apothéosis “Deification in essence.”   Latin Grace is created (but “supernatural”—i.e. not part of nature)—a form or quality of the soul, with form being understood as a definer or  realizer—a sort of actualization.

      Two terms still unbaptized in English that are often encountered in Orthodox writings are noëtic (the adjective that goes with noûs; see above) and neptic.   
      While noûs is often rendered as (and patristically located in the) "heart," there is no cognate adjective (e.g. cordial, hearty) that is suitable; therefore, noëtic can provisionally be rendered as "transcendent."  The Kantianesque overtones are not great, but at least they bring out the intellectual side of the transintellectual import of the word. 
     Neptic (corresponding with the noun nepsis "sobriety"; the "e" is eta) is just as difficult, though not as frequently found in Orthodox literature.  We can let "circumspect," "level-headed," or "well-balanced" suffice until someone comes up with something more adequate.  Nepsis itself could be rendered "sober outlook," "restraint," or "calm watchfulness/ absorption"—possibly even "undistracted condition," or still more marginally, "unperturbability."

A FATAL CONFUSION 

     In reading and commenting on traditional philosophy and related sub- jects, one must carefully distinguish what is NORMAL from what is NATURAL.  What is normal is what IS—a matter of statistical predomi- nance.  What is natural is what OUGHT to be in the specific sense of conforming with and promoting the true nature of a being.  Many that should have known better have gone astray over this distinction.

OVERLAP

      Readers should be apprised of the fact that the boundaries of a word in one language do not necessarily correspond to the boundaries of its gloss (translation) in another language:  The meaning(s) of a Greek word may cover some of the semantic space of more than one word in English; and the meaning(s) of an English word may cover some of the semantic space of more than one word in Greek.