But, while Marx's belief that capital and labor were substitutes, not complements, was a mistake in his own age, and for more than a century to follow, it may not be a mistake today.
1	But	but	CCONJ	CC	_	39	cc	_	SpaceAfter=No
2	,	,	PUNCT	FF	_	39	punct	_	_
3	while	while	SCONJ	CS	_	19	mark	_	_
4	Marx	Marx	PROPN	SP	_	6	nmod	_	SpaceAfter=No
5	's	's	PART	PART	_	4	case	_	_
6	belief	belief	NOUN	S	Number=Sing	19	nsubj	_	_
7	that	that	SCONJ	CS	_	12	mark	_	_
8	capital	capital	NOUN	S	Number=Sing	12	nsubj	_	_
9	and	and	CCONJ	CC	_	10	cc	_	_
10	labor	labor	NOUN	S	Number=Sing	8	conj	_	_
11	were	be	AUX	V	Mood=Ind|Number=Sing|Person=2|Tense=Past|VerbForm=Fin	12	cop	_	_
12	substitutes	substitute	NOUN	S	Number=Plur	6	acl	_	SpaceAfter=No
13	,	,	PUNCT	FF	_	15	punct	_	_
14	not	not	PART	PART	Polarity=Neg	15	advmod	_	_
15	complements	complement	NOUN	S	Number=Plur	12	conj	_	SpaceAfter=No
16	,	,	PUNCT	FF	_	15	punct	_	_
17	was	be	AUX	V	Mood=Ind|Number=Sing|Person=3|Tense=Past|VerbForm=Fin	19	cop	_	_
18	a	a	DET	RI	Definite=Ind|Number=Sing|PronType=Art	19	det	_	_
19	mistake	mistake	NOUN	S	Number=Sing	39	advcl	_	_
20	in	in	ADP	E	_	23	case	_	_
21	his	his	DET	AP	Poss=Yes|PronType=Prs	23	nmod:poss	_	_
22	own	own	ADJ	A	Degree=Pos	23	amod	_	_
23	age	age	NOUN	S	Number=Sing	19	obl	_	SpaceAfter=No
24	,	,	PUNCT	FF	_	30	punct	_	_
25	and	and	CCONJ	CC	_	30	cc	_	_
26	for	for	ADP	E	_	30	case	_	_
27	more	more	ADJ	A	Degree=Cmp	30	amod	_	_
28	than	than	ADP	E	_	27	fixed	_	_
29	a	a	DET	RI	Definite=Ind|Number=Sing|PronType=Art	30	det	_	_
30	century	century	NOUN	S	Number=Sing	23	conj	_	_
31	to	to	PART	PART	_	32	mark	_	_
32	follow	follow	VERB	V	VerbForm=Inf	30	acl	_	SpaceAfter=No
33	,	,	PUNCT	FF	_	19	punct	_	_
34	it	it	PRON	PE	Number=Sing|Person=3|PronType=Prs	39	nsubj	_	_
35	may	may	AUX	VM	Mood=Ind|Person=3|Tense=Pres|VerbForm=Fin	39	aux	_	_
36	not	not	PART	PART	Polarity=Neg	39	advmod	_	_
37	be	be	AUX	V	VerbForm=Inf	39	cop	_	_
38	a	a	DET	RI	Definite=Ind|Number=Sing|PronType=Art	39	det	_	_
39	mistake	mistake	NOUN	S	Number=Sing	0	root	_	_
40	today	today	ADV	B	_	39	advmod	_	SpaceAfter=No
41	.	.	PUNCT	FS	_	39	punct	_	_
