The Sunday Crossword, Sunday 24 Jul 2016

ACROSS
1   Iron commitment ultimately put into state security (6) SAFETY {FE}{c...nT} in {SAY}
4   Correct answer about cleric (8) ACCURATE {A}{C}{CURATE}
10 Mineral starts to appear blue and silver in turn (9) ALABASTER {Ap...r}{Blue}{And}{Si...r} in {ALTER}
11 Feeling essential to brass ensemble (5) SENSE [T]
12 Text's aims lie in unravelling philosophy (14) EXISTENTIALISM*
14 Charges to screen large fights (5) DUELS {DUE{L}S}
16 Trace idea reforms wipe out (9) ERADICATE*
17 State endless desire, then deceive with misdeed (9) WISCONSIN {WISh}{CON}{SIN}
19 Joint work about semi-aquatic mammal (5) HIPPO {HIP}{PO<=}
21 Opposing action from token ruler? (14) COUNTERMEASURE {COUNTER}{MEASURE}
24 Notice colour around snake (5) ADDER {AD}{DER<=}
25 Queen with sign joined by secretary in court before artist (9) CLEOPATRA {C{LEO}{PA}T}{RA}
26 Settle with noble publican (8) LANDLORD {LAND}{LORD}
27 Performed unusually adeptly, short of time (6) PLAYED ADEPtLY*

DOWN
1   Reduced depth in amendment of second law (6-4) SCALED-DOWN {D} in {SECOND+LAW}*
2   Delicate piece of cloth in folder (7) FRAGILE {F{RAG}ILE}
3   Child, when tucked in, warm (5) TOAST {TO{AS}T}
5   Character at home with a burden accepting new one? (8,6) CARDINAL NUMBER {CARD}{IN}{A}{L {N}UMBER}
6   Comedian finally among us, mischievous kind (9) UNSELFISH {U{c...aN}S}{ELFISH}
7   Inability to remember bad men dividing continent (7) AMNESIA {A{MEN*}SIA}
8   Always this crossword? Not half (4) EVER EVERyman
9   Painter showing variety of planet's scenery (7,7) STANLEY SPENCER*
13 Earlier group full of energy loudly followed by rising idol (10) BEFOREHAND {E}{F}{HERO<=} in {BAND}
15 Rogue doctor absorbed by working on clues (9) SCOUNDREL {DR} in {CLUES+ON}*
18 Today, surrounded by signs of approval, climbing mountain (7) SNOWDON {NODS<=} around {NOW}
20 Quiet duck, truly wild fowl (7) POULTRY {P}{O}{TRULY*}
22 Shock upset father and friend (5) APPAL {AP<=}{PAL}
23 End story in hearing (4) TAIL (~tale)

GRID