Rigidly

  address to the unco guid, or the rigidly righteous
  my son, these maxims make a rule,
  an' lump them aye thegither;
  the rigid righteous is a fool,
  the rigid wise anither:
  the cleanest corn that ere was dight
  may hae some pyles o' caff in;
  so ne'er a fellow-creature slight
  for random fits o' daffin.
  (solomon.—eccles. ch. vii. verse 16.)
  o ye wha are sae guid yoursel',
  sae pious and sae holy,
  ye've nought to do but mark and tell
  your neibours' fauts and folly!
  whase life is like a weel-gaun mill,
  supplied wi' store o' water;
  the heaped happer's ebbing still,
  an' still the clap plays clatter.
  hear me, ye venerable core,
  as counsel for poor mortals
  that frequent pass douce wisdom's door
  for glaikit folly's portals:
  i, for their thoughtless, careless sakes,
  would here propone defences—
  their donsie tricks, their black mistakes,
  their failings and mischances.
  ye see your state wi' theirs compared,
  and shudder at the niffer;
  but cast a moment's fair regard,
  what maks the mighty differ;
  discount what scant occasion gave,
  that purity ye pride in;
  and (what's aft mair than a' the lave),
  your better art o' hidin.
  think, when your castigated pulse
  gies now and then a wallop!
  what ragings must his veins convulse,
  that still eternal gallop!
  wi' wind and tide fair i' your tail,
  right on ye scud your sea-way;
  but in the teeth o' baith to sail,
  it maks a unco lee-way.
  see social life and glee sit down,
  all joyous and unthinking,
  till, quite transmugrified, they're grown
  debauchery and drinking:
  o would they stay to calculate
  th' eternal consequences;
  or your more dreaded hell to state,
  damnation of expenses!
  ye high, exalted, virtuous dames,
  tied up in godly laces,
  before ye gie poor frailty names,
  suppose a change o' cases;
  a dear-lov'd lad, convenience snug,
  a treach'rous inclination—
  but let me whisper i' your lug,
  ye're aiblins nae temptation.
  then gently scan your brother man,
  still gentler sister woman;
  tho' they may gang a kennin wrang,
  to step aside is human:
  one point must still be greatly dark,—
  the moving why they do it;
  and just as lamely can ye mark,
  how far perhaps they rue it.
  who made the heart, 'tis he alone
  decidedly can try us;
  he knows each chord, its various tone,
  each spring, its various bias:
  then at the balance let's be mute,
  we never can adjust it;
  what's done we partly may compute,
  but know not what's resisted.