{1d04 attributus}

Meaning Attributes are infinite spaces. Ethica claims there must be an infinite number of them (1p10s), each of which "expresses eternal and infinite essentiality" (of God = natura-sense 2 = substance) {1d06}, but human beings perceive only two: extension and thought. Every limited thing (res, modus) is in only one attribute. To understand some thing (res, modus), say, a geometrical figure, I need to understand that it is in an infinite space, a geometrical plane, in which it is drawn. When someone draws a geometrical figure, you are asked to take the sheet of paper, blackboard or sand surface on which it is drawn for that infinite space (nowadays called a cartesian product). Similarly, extended things (also called corpora, bodies) are all in the infinite attribute of extension. This is related  to Descartes' concept of the the physical universe. The other infinite attribute we perceive contains another kind of modi called ideas, thoughts, knowledge. These are in the attribute of thought (cogitatio).
Things in both attributes are called modi or res, though res also is used in a restricted sense of only referring to extended modi.
The human being, by being a mind and a body in unity (unita), is part of (or: is a modus in) both attributes and thus liable to (cartesian) impacts ("hits" literally) from other modi in both infinite cartesian product-spaces called attributes.. But the attributes themselves cannot be said to make impacts. They are just two disjunct infinite spaces in which modi, each of their kind (genus) move around affecting each other. Culminating in the ordo et connectio proposition {2p07} it is claimed that causation is only within, never across attributes and every thing and every causal chain in one attribute corresponds 1 to 1 to a similar structure in the other attribute, since the attributes mirror the same substance (more introduction in  getting started, technical details in Appendix to pp1p02 res concerning {2p07})
Subsets (kinds) extensio, cogitatio
Occurrence [geomap]
{1d02 in suo genere finita^absoluta infinita}                       ... bodies and thoughts are in different attributes hence cannot limit each other...
... a body is called finite because we always conceive another greater body. So, also, a thought is limited by another thought, but a body is not limited by thought, nor a thought by body. ... corpus dicitur finitum quia aliud semper majus concipimus. Sic cogitatio alia cogitatione terminatur. At corpus non terminatur cogitatione nec cogitatio corpore.
{1d06 deus}                                                                                        ...attributes can express eternal and infinite essentiality...
...By God, I mean a being absolutely infinite-that is, a substance consisting in infinite attributes, of which each expresses eternal and infinite essentiality. ...Per Deum intelligo ens absolute infinitum hoc est substantiam constantem infinitis attributis quorum unumquodque aeternam et infinitam essentiam exprimit.
{1p04 distinctae attributorum vel affectionum}                 ...substances means the same as "their attributes and affectiones"...
... the substances, or, in other words ... their attributes and modifications... ...substantias sive  [prf-eqv] quod idem est ... earum attributa earumque affectiones...
{1p05 in rerum natura}                                                                   ...nature and attribute mean the same...
...nature or attribute. ...naturae sive  [mng-eqv]  attributi.
{1p10 attributum concipi per se}                                             ... debere concipere per se not only for causa sui (= God = natura-sense 2 = substance) but also for attributes ...
...Each particular attribute of the one substance must be conceived through itself. ...Unumquodque unius  substantiae attributum per se concipi debet.
...An attribute is that which the intellect perceives of substance, as constituting its essence (Def. iv.), and, therefore, must be conceived through itself... ... Attributum enim est id quod intellectus de substantia percipit tanquam ejus essentiam constituens (per definitionem 4 {1d04}) adeoque ...per se concipi debet...
                                                                                     ... a puzzling suggestion of symmetry: res extensa refers to a modus in the attribute of extension, but res cogitans does NOT refer to a similar modus (thought, idea) in the attribute of thinking  but to an operation on such modi, the operation of thinking (cogitatio-operatio) ...
{2p01} 1. Thought is an attribute of God 2. God is a thinking thing. 1. Cogitatio attributum Dei est 2. Deus est res cogitans.
{2p02} 1. Extension is an attribute of God 2. God is an extended thing 1. Extensio attributum Dei est 2. Deus est res extensa.
{2p05 Esse formale idearum}                                                    ... run up to ordo et connexio theorem {2p07} ... an idea is not caused by the thing the idea is about...
... The actual being of ideas owns God as its cause, only in so far as he is considered as a thinking thing, not in so far as he is unfolded in any other attribute; that is, the ideas both of the attributes of God and of particular things do not own as their efficient cause their objects (ideata) or the things perceived, but God himself in so far as he is a thinking thing. ... Esse  formale idearum Deum quatenus tantum ut res cogitans consideratur, pro causa agnoscit et non quatenus alio attributo explicatur. Hoc est tam Dei attributorum quam rerum singularium ideae non ipsa ideata sive [mng-eqv]  res perceptas pro causa efficiente agnoscunt sed ipsum Deum quatenus est res cogitans.
{2p06 modi Deum causa attributo}                                        ... run up to ordo et connexio theorem {2p07} ... attributes are independent channels to indirectly perceive the substance ...
...The modes of any given attribute are caused by God, in so far as he is considered through the attribute of which they are modes, and not in so far as he is considered through any other attribute. ... Cujuscunque attributi  modi Deum quatenus tantum sub illo attributo cujus modi sunt et non quatenus sub ullo alio consideratur, pro causa habent.

{2p07 ordo et connexio}                                                              ... {2p05} and {2p06} lead up to this famous ordo et connexio theorem... rerum ^ idearum is subsequently referred to as rerum ^ causarum ... attributes independently mirror substance, hence mirror the same, hence have the same structure ...

... The order and connection of ideas is the same as the order and connection of things. ... ordo et connexio idearum idem est ac ordo et connexio rerum.
2p07s substantia cogitans et substantia extensa una      ... puzzling, if not dangerous quote ... the attribute of extension (harbouring res extensae), is here associated with an expression unique in Ethica: substantia extensa. The attribute of thought however is associated NOT with res cogitandi but is called substantia cogitans, referring NOT to idea = res cogitandi but to cogitatio-operatio, the operation that produces ideas. A few words further down, in "idea illius modi", the opposition is changed back from  cogitatio-operatio to idea ( cogitatio-res). Res is used here as res sense 3, that is: NOT to referring to modi, as it elsewhere does in expressions like res extensa or (in {1p14c2}) rem cogitantem, but for the substantial thing that expresses itself in two modi (1. an extended modus and 2. a modus cogitandi) ... moreover, in the expression in natura existens the term natura is used, absolutely unique in Ethica, as extended nature ... but at the end of the quote, the expression totius naturae refers again to the rare but not unique meaning of natura-substantia. [more: notes page on natura]
... substance thinking and substance extended are one and the same substance, comprehended now through one attribute, now through the other. So, also, a mode of extension and the idea of that mode are one and the same thing, though expressed in two ways ... ... substantia cogitans et substantia extensa una eademque est substantia quae jam sub hoc jam sub illo attributo comprehenditur. Sic etiam modus extensionis et idea illius modi una eademque est res sed duobus modis expressa...
... For instance, a circle existing in nature, and the idea of a circle existing, which is also in God, are one and the same thing displayed through different attributes.  Thus, whether we conceive nature under the attribute of extension, or under the attribute of thought, or under any other attribute, we shall find the same order, or one and the same chain of causes-that is, the same things following in either case... ... Exempli gratia circulus in natura existens et idea circuli existentis quae etiam in Deo est, una eademque est res quae per diversa attributa explicatur et ideo sive naturam sub extensionis sive sub attributo cogitationis sive sub alio quocunque concipiamus, unum eundemque ordinem sive unam eandemque causarum connexionem hoc est easdem res invicem sequi reperiemus.
...God is the cause of an idea-for instance, of the idea of a circle,-in so far as he is a thinking thing; and of a circle, in so far as he is an extended thing, simply because the actual being of the idea of a circle can only be perceived as a proximate cause through another mode of thinking, and that again through another, and so on to infinity; ...Deus sit causa ideae exempli gratia circuli quatenus tantum est res cogitans et circuli quatenus tantum est res extensa nisi quia esse formale ideae circuli non nisi per alium cogitandi modum tanquam causam proximam et ille iterum per alium et sic in infinitum, potest percipi
so that, so long as we consider things as modes of thinking, we must explain the order of the whole of nature, or the whole chain of causes, through the attribute of thought only. ita ut quamdiu res ut cogitandi modi considerantur, ordinem totius naturae sive causarum connexionem per solum cogitationis attributum explicare debemus
... in so far as we consider things as modes of extension, we must explain the order of the whole of nature through the attributes of extension only... et quatenus ut modi extensionis considerantur, ordo etiam totius naturae per solum extensionis attributum explicari debet...

Equivalence claims involving attributus
{1d04} [notes] 1. attribute 2. that which the intellect perceives as constituting the essence of substance. 1. attributum 2. id quod intellectus de substantia percipit tanquam ejusdem essentiam constituens.
{1d06} [notes] 1. God 2. a being absolutely infinite-that is, a substance consisting in infinite attributes, of which each expresses eternal and infinite essentiality. 1. Deum 2. ens absolute infinitum hoc est substantiam constantem infinitis attributis quorum unumquodque aeternam et infinitam essentiam exprimit.
{1p05} [About substances] 1. nature 2. attributes [De substantiis] 1. naturae 2. attributi.
{1p25c} 1. Individual things 2. modifications [Lat: affectiones] of the attributes of God 3. modes by which the attributes of God are expressed in a fixed and definite manner. 1. Res particulares 2. Dei attributorum affectiones 3. modi quibus Dei attributa certo et determinato modo exprimuntur.
{1p28} 1. Wherefore it must follow from 2. be conditioned for, existence and action by God or one of his attributes, in so far as the latter are modified by some modification which is finite, and has a conditioned existence. 1. sequi 2. ad existendum et operandum determinari a Deo vel  [excl exh] aliquo ejus attributo quatenus modificatum est modificatione quae finita est et determinatam habet existentiam.
{2p01} 1. Thought is an attribute of God 2. God is a thinking thing. 1. Cogitatio attributum Dei est 2. Deus est res cogitans.
{2p02} 1. Extension is an attribute of God 2. God is an extended thing 1. Extensio attributum Dei est 2. Deus est res extensa.