incredible；　what　shall　we　say　of　infants？　A　man　of　ripe　age　deems　their
  nature　so　unlike　his　own；　that　he　can　only　be　persuaded　that　he　too　has
  been　an　infant　by　the　analogy　of　other　men。　However；　I　prefer　to　leave　such
  questions　undiscussed；　lest　I　should　give　ground　to　the　superstitious　for
  raising　new　issues。
  Prop。　XL。　Whatsoever　conduces　to　man's
  social　life；　or　causes　men　to　live
  together　in　harmony；　is　useful；　whereas
  whatsoever　brings　discord　into　a　State　is　bad。
  Proof。…　For　whatsoever　causes　men　to　live　together　in　harmony　also　causes
  them　to　live　according　to　reason　（IV：xxxv。）；　and　is　therefore　（IV：xxvi。
  and　IV：xxvii。）　good；　and　（for　the　same　reason）　whatsoever　brings　about
  discord　is　bad。　Q。E。D。
  Prop。　XLI。　Pleasure　in　itself　is　not
  bad　but　good：　contrariwise；　pain　in
  itself　is　bad。
  Proof。…　Pleasure　（III：xi。&Note）　is　emotion；　whereby　the　body's　power　of
  activity　is　increased　or　helped；　pain　is　emotion；　whereby　the　body's　power
  of　activity　is　diminished　or　checked；　therefore　（IV：xxxviii。）　pleasure　in
  itself　is　good；　&c。　Q。E。D。
  Prop。　XLII。　Mirth　cannot　be　excessive；
  but　is　always　good；　contrariwise；
  Melancholy　is　always　bad。
  Proof。…　Mirth　（see　its　Def。　in　III：xi。Note）　is　pleasure。　which；　in　so
  far　as　it　is　referred　to　the　body；　consists　in　all　parts　of　the　body　being
  affected　equally：　that　is　（III：xi。）；　the　body's　power　of　activity　is
  increased　or　aided　in　such　a　manner；　that　the　several　parts　maintain　their
  former　proportion　of　motion　and　rest；　therefore　Mirth　is　always　good
  （IV。　xxxix。）；　and　cannot　be　excessive。　But　Melancholy　（see　its　Def。　in
  the　same　note　to　III：xi。Note）　is　pain；　which；　in　so　far　as　it　is　referred
  to　the　body；　consists　in　the　absolute　decrease　or　hindrance　of　the　body's
  power　of　activity；　therefore　（IV：xxxviii。）　it　is　always　bad。　Q。E。D。
  Prop。　XLIII。　Stimulation　may　be　excessive
  and　bad；　on　the　other　hand；　grief　may　be
  good；　in　so　far　as　stimulation　or　pleasure
  is　bad。
  Proof。…　Localized　pleasure　or　stimulation　（titillatio）　is　pleasure；　which；
  in　so　far　as　it　is　referred　to　the　body；　consists　in　one　or　some　of　its
  parts　being　affected　more　than　the　rest　（see　its　Definition；　III：xi。Note）；
  the　power　of　this　emotion　may　be　sufficient　to　overcome　other　actions　of
  the　body　（IV：vi。）；　and　may　remain　obstinately　fixed　therein；　thus　rendering
  it　incapable　of　being　affected　in　a　variety　of　other　ways：　therefore
  （IV：xxxviii。）　it　may　be　bad。　Again；　grief；　which　is　pain；　cannot　as　such
  be　good　（IV：xli。）。　But；　as　its　force　and　increase　is　defined　by　the　power
  of　an　external　cause　compared　with　our　own　（IV：v。）；　we　can　conceive
  infinite　degrees　and　modes　of　strength　in　this　emotion　（IV：iii。）；
  we　can；　therefore；　conceive　it　as　capable　of　restraining　stimulation；
  and　preventing　its　becoming　excessive；　and　hindering　the　body's
  capabilities；　thus；　to　this　extent；　it　will　be　good。　Q。E。D。
  Prop。　XLIV。　Love　and　desire　may　be　excessive。
  Proof。…　Love　is　pleasure；　accompanied　by　the　idea　of　an　external　cause
  （Def_of_Emotions：vi。）；　therefore　stimulation；　accompanied　by　the　idea　of
  an　external　cause　is　love　（III：xi。Note）；　hence　love　maybe　excessive。
  Again；　the　strength　of　desire　varies　in　proportion　to　the　emotion　from
  which　it　arises　（III：xxxvii。）。　Now　emotion　may　overcome　all　the　rest　of
  men's　actions　（IV：vi。）；　so；　therefore；　can　desire；　which　arises　from　the
  same　emotion；　overcome　all　other　desires；　and　become　excessive；　as　we
  showed　in　the　last　proposition　concerning　stimulation。
  Note。…　Mirth；　which　I　have　stated　to　be　good；　can　be　conceived　more　easily
  than　it　can　be　observed。　For　the　emotions；　whereby　we　are　daily　assailed；
  are　generally　referred　to　some　part　of　the　body　which　is　affected　more　than
  the　rest；　hence　the　emotions　are　generally　excessive；　and　so　fix　the　mind
  in　the　contemplation　of　one　object；　that　it　is　unable　to　think　of　others；
  and　although　men；　as　a　rule；　are　a　prey　to　many　emotions　…　and　very　few
  are　found　who　are　always　assailed　by　one　and　the　same　…　yet　there　are
  cases；　where　one　and　the　same　emotion　remains　obstinately　fixed。　We
  sometimes　see　men　so　absorbed　in　one　object；　that；　although　it　be　not
  present；　they　think　they　have　it　before　them；　when　this　is　the　case　with　a
  man　who　is　not　asleep；　we　say　he　is　delirious　or　mad；　nor　are　those　persons
  who　are　inflamed　with　love；　and　who　dream　all　night　and　all　day　about
  nothing　but　their　mistress；　or　some　woman；　considered　as　less　mad；　for
  they　are　made　objects　of　ridicule。　But　when　a　miser　thinks　of　nothing　but
  gain　or　money；　or　when　an　ambitious　man　thinks　of　nothing　but　glory；　they
  are　not　reckoned　to　be　mad；　because　they　are　generally　harmful；　and　are
  thought　worthy　of　being　hated。　But；　in　reality；　Avarice；　Ambition；　Lust；
  &c。；　are　species　of　madness；　though　they　may　not　be　reckoned　among　diseases。
  Prop。　XLV。　Hatred　can　never　be　good。
  Proof。…　When　we　hate　a　man；　we　endeavour　to　destroy　him　（III。xxxix。）；
  that　is　（IV：xxxvii。）；　we　endeavour　to　do　something　that　is　bad。
  Therefore；　&c。　Q。E。D。
  N。B。　Here；　and　in　what　follows；　I　mean　by　hatred　only　hatred　towards　men。
  Corollary　I。…　Envy；　derision；　contempt；　anger；　revenge；　and　other　emotions
  attributable　to　hatred；　or　arising　therefrom；　are　bad；　this　is　evident　from
  III：xxxix。　and　IV：xxxvii。
  Corollary　II。…　Whatsoever　we　desire　from　motives　of　hatred　is　base；　and　in
  a　State　unjust。　This　also　is　evident　from　III：xxxix。；　and　from　the
  definitions　of　baseness　and　injustice　in　IV：xxxvii。Note。
  Note。…　Between　derision　（which　I　have　in　Coroll。　I。　stated　to　be　bad）　and
  laughter　I　recognize　a　great　difference。　For　laughter；　as　also　jocularity；
  is　merely　pleasure；　therefore；　so　long　as　it　be　not　excessive；　it　is　in
  itself　good　（IV：xli。）。　Assuredly　nothing　forbids　man　to　enjoy　himself；
  save　grim　and　gloomy　superstition。　For　why　is　it　more　lawful　to　satiate
  one's　hunger　and　thirst　than　to　drive　away　one's　melancholy？　I　reason；　and
  have　convinced　myself　as　follows：　No　deity；　nor　anyone　else；　save　the
  envious；　takes　pleasure　in　my　infirmity　and　discomfort；　nor　sets　down　to　my
  virtue　the　tears；　sobs；　fear；　and　the　like；　which　axe　signs　of　infirmity　of
  spirit；　on　the　contrary；　the　greater　the　pleasure　wherewith　we　are　affected；
  the　greater　the　perfection　whereto　we　pass；　in　other　words；　the　more　must
  we　necessarily　partake　of　the　divine　nature。　Therefore；　to　make　use　of　what
  comes　in　our　way；　and　to　enjoy　it　as　much　as　possible　（not　to　the　point　of
  satiety；　for　that　would　not　be　enjoyment）　is　the　part　of　a　wise　man。　I　say
  it　is　the　part　of　a　wise　man　to　refresh　and　recreate　himself　with　moderate
  and　pleasant　food　and　drink；　and　also　with　perfumes；　with　the　soft　beauty
  of　growing　plants；　with　dress；　with　music；　with　many　sports；　with　theatres；
  and　the　like；　such　as　every　man　may　make　use　of　without　injury　to　his
  neighbour。　For　the　human　body　is　composed　of　very　numerous　parts；　of
  diverse　nature；　which　continually　stand　in　need　of　fresh　and　varied
  nourishment；　so　that　the　whole　body　may　be　equally　capable　of　performing
  all　the　actions；　which　follow　from　the　necessity　of　its　own　nature；　and；
  consequently；　so　that　the　mind　may　also　be　equally　capable　of　…
  understanding　many　things　simultaneously。　This　way　of　life；　then；　agrees
  best　with　our　principles；　and　also　with　general　practice；　therefore；　if
  there　be　any　question　of　another　plan；　the　plan　we　have　mentioned　is　the
  best；　and　in　every　way　to　be　commended。　There　is　no　need　for　me　to　set
  forth　the　matter　more　clearly　or　in　more　detail。
  Prop。　XLVI。　He；　who　lives　under　the
  guidance　of　reason；　endeavours；　as
  far　as　possible；　to　render　back　love；
  or　kindness；　for　other　men's　hatred；
  anger；　contempt；　&c。；　towards　him。
  Proof。…　All　emotions　of　hatred　are　bad　（IV：xlv。Coroll。i。）；　therefore　he　who
  lives　under　the　guidance　of　reason　will　endeavour；　as　far　as　possible；　to
  avoid　being　assailed　by；　such　emotions　（IV：xix。）；　consequently；　he　will
  also　endeavour　to　prevent　others　being　so　aspect　（IV：xxxvii。）。　But　hatred
  is　increased　by　being　reciprocated；　and　can　be　quenched　by　love　III：xliii。）；
  so　that　hatred　may　pass　into　love　（III：xliv。）；　therefore　he　who　lives　under
  the　guidance　of　reason　will　endeavour　to　repay　hatred　with　love；　that　is；
  with　kindness。　Q。E。D。
  Note。…　He　who　chooses　to　avenge　wrongs　with　hatred　is　assuredly；　wretched。
  But　he；　who　strives　to　conquer　hatred　with　love；　fights　his　battle　in　joy
  and　confidence；　he　withstands　many　as　easily　as　one